test: Fix Sanity Test 1 image paths

[dcalhoun]

• Fix Sanity Test 1 image paths. Previously, the test description was updated, but the tests were not re-run to generate new file paths.
• Nest Columns slider test beneath Sanity Test 1 description. The lack of nesting was an oversight. The rest of the tests are nested.
• Remove decreased failure threshold for sliders test. This caused false failures. It appears the test is able to identify true failures with the default 0.1% failure threshold

To test: n/a

PR submission checklist:

• I have considered adding unit tests where possible.
• I have considered if this change warrants user-facing release notes more info and have added them to RELEASE-NOTES.txt if necessary.

[peril-wordpress-mobile]

Wanna run full suite of Android and iOS UI tests? Click here and 'Approve' CI job!

[derekblank]

LGTM! 🚀

[fluiddot]

Seems the E2E tests related to Sanity Test 1 are failing in trunk after this PR was merged (reference). I noticed the optional UI tests weren't triggered in the last commit of this PR, since the Sanity Test suite 1 is only run in the Test iOS/Android on Device - Full job, it would be great to run it to check for potential failures.

I'll restore the branch and run them as a last check.

[fluiddot]

Seems the E2E tests related to Sanity Test 1 are failing in trunk after this PR was merged (reference). I noticed the optional UI tests weren't triggered in the last commit of this PR, since the Sanity Test suite 1 is only run in the Test iOS/Android on Device - Full job, it would be great to run it to check for potential failures.

I'll restore the branch and run them as a last check.

As it happened in the trunk commit, the E2E tests failed when triggering the full tests via gutenberg-mobile/Optional UI Tests (reference). In any case, this issue has been fixed in #5606 🎊 .