Redesign DevLoadingView (Android)

[huntie]

Summary

Android counterpart to #58866.

The Android dev loading banner spans the full width under the status bar. This brings it in line with the iOS capsule below in this stack.

• Solid pill design, centered, 12dp below the status bar or 16dp from the top edge without one.
• Kept clear of the side insets.
• Round close button in place of the "Dismiss ✕" text button.
• Scales and fades in and out, matching iOS.
• Fix: A message hidden right after it shows, such as a fast Fast Refresh, now stays up for at least 0.6s, matching iOS. Previously, It was dismissed before it ever appeared.

Changelog:
[Android][Changed] - Dev loading banner: Redesign in-app Loading/Fast Refresh banner
[Android][Fixed] - Dev loading banner: Reduce flickering 0s Fast Refresh banners

Test Plan

./gradlew :packages:rn-tester:android:app:installDebug -PreactNativeArchitectures=arm64-v8a

• ✅ RNTester builds and runs on the Pixel_10a emulator (API 37).
• ✅ Each state shows the capsule, with the close button on the disconnected banner.
• ✅ Measured top placement: 12dp below a 142px status bar.
• ⚠️ No Android tests cover this view.

App states, Pixel 10a

	Light	Dark
Loading
Fast Refresh
Disconnected

🎬 End to end app load, Fast Refresh

android-pill-e2e-load-refresh.mov

[github-actions]

Caution

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