fix(widgets): define RTL support

[david-allison]

Note

Assisted-by: Claude Fable 5

Purpose / Description

The widget configuration layout uses start/end attributes

We will add checkDependencies = true for 21500 supportsRtl will be needed when lint checks this dependency.

Fixes

• Part of multimodule support: move strings to :common:android #21500

Checklist

• 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

[criticalAY]

LGTM!