Update cloud storage limit title

[ashiagr]

Description

This updates cloud storage string title from 10GB to 20GB.

This targets v7.47 beta branch.

We should probably add a task to update this title dynamically from the remote config.

Testing Instructions

It should be sufficient to just check the strings file.

Screenshots or Screencast

Old	New

Checklist

• If this is a user-facing change, I have added an entry in CHANGELOG.md
• Ensure the linter passes (./gradlew spotlessApply to automatically apply formatting/linting)
• I have considered whether it makes sense to add tests for my changes
• All strings that need to be localized are in modules/services/localization/src/main/res/values/strings.xml
• Any jetpack compose components I added or changed are covered by compose previews

I have tested any UI changes...

• with different themes
• with a landscape orientation
• with the device set to have a large display and font size
• for accessibility with TalkBack

[mchowning]

Looks good. I'll hold off on cutting a new beta since this is a relatively trivial change. Let me know if you think we should go ahead and cut a new beta though.