Follow up to first run dialog on Windows

[rebron]

Description

Update text and button actions to reflect design.

Design/Expected result

see: #21694 (comment)

Brave version (brave://version info)

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Miscellaneous Information:

Follow-up from #21464

[bradleyrichter]

Title: Ready for the best privacy online?

Body: Set Brave as your default browser to get Brave’s privacy protections on every web page you open.

No button: Maybe later

Yes button: Set Brave as default

Preview:

[MadhaviSeelam]

Verified Complete using

Brave	1.38.70 Chromium: 100.0.4896.46 (Official Build) beta (64-bit)
Revision	5ca33821b2211805855c77d334353d27c616a7ca-refs/branch-heads/4896@{#584}
OS	Windows 11 Version 21H2 (Build 22000.556)

Logged #21954 for Testcases 2, 3, 4

Testcase 1: `Set Brave as default` browser

• Clean install
• Launch Brave
• First run dialog Ready for the best privacy online? is displayed
• Clicked Set Brave as default button
• Verified dialog design matches to the mockup
• Navigated to brave://settings
• Verified the entry Brave is your default browser in the settings page

Testcase 2: `Make Default` button should be available in `brave://settings`

• Clean install
• Launch Brave
• First run dialog Ready for the best privacy online? is displayed
• Clicked Maybe later to dismiss the dialog
• Navigate to brave://settings
• Verify Default browser entry shows Make default button
• Click on 'Make default' button to Set Brave as default browser

Testcase 3: Click `x` on the dialog

• Clean Profile
• Launch Brave
• First run dialog Ready for the best privacy online? is displayed
• Clicked x to dismiss the dialog
• Navigate to brave://settings
• Verify Default browser entry shows Make default button
• Click on 'Make default' button to Set Brave as default browser

Testcase 4: The dialog should display buttons same order as the mockup

• Clean profile
• Launch Brave
• First run dialog Ready for the best privacy online? should be displayed
• Verified the dialog design matches to the mockup
• The order of the buttons should be Maybe later followed by Set Brave as default

[kjozwiak]

We'll need to re-test this via 1.37.x as we're uplifting it into the 1.37.x maintenance release via brave/brave-core#12692. The above will require 1.37.111 or higher for verification using 1.37.x.

[GeetaSarvadnya]

Verification PASSED on

Brave | 1.37.113 Chromium: 100.0.4896.88 (Official Build) (64-bit)
-- | --
Revision | 4450653bfa91182e85723d8f1dee64dd6ce40ed4-refs/branch-heads/4896@{#1086}
OS | Windows 10 Version 21H2 (Build 19044.1586)

• Verification is covered in Enable first run dialog on Windows #21464 (comment)