[Reader IA] Update some minor UI style in Reader buttons and feed empty states

[thomashorta]

Fixes #20028

Updates to

• the style of some empty states of reader feeds (such as the Discover, Subscriptions, Liked, Saved) to have a black button
• text in the Subscriptions empty state to match Figma (zQnohyMpLzBzQ5jzMMKni3-fi-2848_17970)
• chips and button in the "Follow Tags" or Reader Interests screen
• illustration used in some empty feeds, such as the "Saved" feed, to match iOS and Web

See video below to see the main changes.

20028-reader-ia-empty-feeds-and-interest-styles-shorter.mp4

Note: same as #19993 there are some pre-existing bugs (related to fetching fields after going to search/manage subscription screens). Those were not fixed here, as this PR is just touching the visual styles and some copies, but the GH issues are open in our backlog.

---

To Test:

I recommend using a secondary test account with no saved or liked posts, and unsubscribe from all blogs and tags, for making it easier to see the empty states.

1. Install and log into Jetpack
2. Go to Reader
3. Make sure to unfollow all blogs and tags (it will make it easier to see the empty feed states)
4. Also make sure to have no Likes or Saved posts
5. Go to the Discover Feed
6. Verify the button style is correct (black)
7. Tap the button
8. Verify the tag chips style is correct (black)
9. Verify the button style is correct both when no tags are selected and when there are tags selected
10. Go back without tapping the button
11. Go to the Liked Feed
12. Verify the button style is correct (black) and the illustration is updated
13. Go to the Saved Feed
14. Verify the button style is correct (black) and the illustration is updated
15. Go to the Subscriptions Feed
16. Verify the button style is correct (black)
17. Verify the text is updated
18. Tap the "Tags" filter (make sure it has 0 tags)
19. Tap the "Suggested tags" button
20. Verify the tag chips style is correct (black)
21. Verify the button style is correct both when no tags are selected and when there are tags selected

Suggestion: also test in dark mode.

---

Regression Notes

1. Potential unintended areas of impact

   • Button style for Actionable Empty View used in other places of the app

2. What I did to test those areas of impact (or what existing automated tests I relied on)

   • Manual testing

3. What automated tests I added (or what prevented me from doing so)

   • N/A, UI and String changes

---

PR Submission Checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

---

UI Changes Testing Checklist:

• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• Talkback.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• Large and small screen sizes. (Tablet and smaller phones)
• Multi-tasking: Split screen and Pop-up view. (Android 10 or higher)

[peril-wordpress-mobile]

	Warnings
⚠️	This PR adds a translatable entry to strings.xml which references another string resource: this usually causes issues with translations.Please make sure to set the translatable="false" attribute here:+ <string name="reader_no_followed_blogs_title">@string/reader_filter_empty_blogs_list_title</string>
⚠️	This PR adds a translatable entry to strings.xml which references another string resource: this usually causes issues with translations.Please make sure to set the translatable="false" attribute here:+ <string name="reader_no_followed_blogs_description">@string/reader_filter_empty_blogs_list_text</string>
⚠️	PR is not assigned to a milestone.
⚠️	PR has more than 300 lines of code changing. Consider splitting into smaller PRs if possible.

Generated by 🚫 dangerJS

[dangermattic]

	3 Warnings
⚠️	View files have been modified, but no screenshot is included in the pull request. Consider adding some for clarity.
⚠️	This PR is larger than 300 lines of changes. Please consider splitting it into smaller PRs for easier and faster reviews.
⚠️	PR is not assigned to a milestone.

Generated by 🚫 Danger

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr20059-49c8f0b
	Commit	49c8f0b
	Direct Download	wordpress-prototype-build-pr20059-49c8f0b.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr20059-49c8f0b
	Commit	49c8f0b
	Direct Download	jetpack-prototype-build-pr20059-49c8f0b.apk

Note: Google Login is not supported on these builds.

[RenanLukas]

Thanks for the PR, @thomashorta

I've checked both light and dark themes and it's working as expected. Code LGTM

[thomashorta]

The last commit I just sent just removes the unused resources that lint is complaining about, so I will merge as soon as the CI finishes building!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (ce45d12) 40.47% compared to head (49c8f0b) 40.47%.
Report is 1 commits behind head on feature/reader-ia.

Additional details and impacted files

@@                Coverage Diff                 @@
##           feature/reader-ia   #20059   +/-   ##
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  Coverage              40.47%   40.47%           
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  Files                   1447     1447           
  Lines                  66779    66779           
  Branches               11028    11028           
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  Hits                   27026    27026           
  Misses                 37269    37269           
  Partials                2484     2484           

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