fix: convert Title Case strings to sentence case in 02-strings.xml

[Yousuf24100286]

Purpose / Description

Few (12 to be precise) of the strings in 02-strings.xml remained. Converted them to string case and fixed the failing test for it.

Fixes

• Fixes [Design] Inconsistent String Casing #15760

Approach

• Changed 12 Title Case strings to sentence case.
• Fixed the failing test.

How Has This Been Tested?

Ran build and test commands to test the changes. All passed.

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

Note: there wasn't much of a huge change to add comments.

[github-actions]

Important

Maintainers: This PR contains Strings changes

1. Sync Translations before merging this PR and wait for the action to complete
2. Review and merge the auto-generated PR in order to sync all user-submitted translations
3. Sync Translations again and merge the PR so the huge automated string changes caused by merging this PR are by themselves and easy to review

[github-actions]

Snapshot diff report vs main. Open screenshot-diff for diffs.

• AllActivitiesScreenshotTest: 2 changes

All 2 changed screenshots

AllActivitiesScreenshotTest

• IntroductionActivity_compare.png
• IntroductionActivity_edgeToEdge_compare.png

[david-allison]

One change needed, rest looks great. Thanks!!