fix(android): support numbersInnerTextColor in config plugin

[giaBaoJS]

Summary

Fixes #1029.

• Allow the Android time picker config plugin to map numbersInnerTextColor to the framework's android:numbersInnerTextColor attribute.
• Document the new time picker styling property.
• Add a regression test that runs the plugin through Expo's prebuild mod compiler and verifies the generated styles.xml, light colors.xml, and dark colors.xml output.

Test Plan

What's required for testing (prerequisites)?

• Install dependencies with yarn install --immutable.

What are the steps to reproduce (after prerequisites)?

• yarn test plugin/src/__tests__/withDateTimePickerStyles.test.js --runInBand — 2 tests passed.
• yarn test --runInBand — 24 tests passed across 4 suites.
• yarn lint — passed with 0 errors (22 existing warnings).
• yarn eslint plugin/src/__tests__/withDateTimePickerStyles.test.js — passed.
• yarn plugin:build — passed.
• yarn prettier --check plugin/src/withDateTimePickerStyles.ts plugin/src/__tests__/withDateTimePickerStyles.test.js docs/android-styling.md — passed.
• yarn pack --dry-run — passed.

Regression evidence:

• Before the whitelist change, the prebuild regression failed in android.styles with Invalid attribute name: numbersInnerTextColor.
• Temporarily removing the final whitelist entry reproduced the same failure, while the unknown-key test continued to pass.
• A deliberately incorrect light-color assertion failed against the generated colors.xml value, confirming the XML assertions are active.
• The final test verifies an unrelated unknown key is still rejected.

yarn flow cannot execute on this ARM64 macOS host because the installed macOS Flow binary is x86_64. Running the Linux ARM64 binary in a container also exposes the existing .flowconfig/dependency version mismatch (^0.217.0 vs 0.278.0) and existing Flow errors. The plugin TypeScript build passes.

Compatibility

OS	Implemented
iOS	❌
Android	✅

Checklist

• I have tested this on a device and a simulator
• I added the documentation in README.md
• I updated the typed files (TS and Flow)
• I added a sample use of the API in the example project (example/App.js)
• I have added automated tests, either in JS or e2e tests, as applicable