Fix invisible Android activity indicator

[dcalhoun]

• Gutenberg: Fix invisible Android activity indicator WordPress/gutenberg#33337

Fixes #3708. Apply a patch for the React Native ActivityIndicator rendering invisible on Android. This applies the same patch that was previously applied to the Embed block to to React Native itself.

The core issue in React Native appears to be wider reaching, but I chose to limit the scope of the patch to the one issue we are currently facing (i.e. invisible activity indicators), as I was concerned applying a deeper, untested change might introduce regressions elsewhere.

This patch can be removed once we upgrade to a React Native version including fixes for the related issues:

• ActivityIndicator works only on iOS facebook/react-native#30056
• ActivityIndicator not visible without color prop on Pixel 3a facebook/react-native#29495
• RN 0.63.1: ActivityIndicator disapearing facebook/react-native#29378.

To test: See WordPress/gutenberg#33337.

PR submission checklist:

• I have considered adding unit tests where possible.
• I have considered if this change warrants user-facing release notes more info and have added them to RELEASE-NOTES.txt if necessary.

[ceyhun]

Approved via WordPress/gutenberg#33337

[peril-wordpress-mobile]

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