[RN] Move RN globals to RN private interface module (#37550)

## Summary

ReactNativeFeatureFlags and fabricUIManager were introduced in
`react-native/react-private-interface` in
react/react-native#57940 and
react/react-native#58398:


https://github.com/react/react-native/blob/73a76ddced2088d925809432fd6b0503f239dbfe/packages/react-native/src/react-private-interface.js#L74


https://github.com/react/react-native/blob/73a76ddced2088d925809432fd6b0503f239dbfe/packages/react-native/src/react-private-interface.js#L87

This migrates the use of globals for those bindings to use the exported
values instead.

## How did you test this change?

Existing tests and Flow.

[FlightReply] Performance improvements when decoding (#37087)

This fixes security vulnerabilities in Server Functions.

[FlightReply] Performance improvements when decoding (#37088)

This fixes security vulnerabilities in Server Functions.

[FlightReply] Performance improvements when decoding (#37089)

This fixes security vulnerabilities in Server Functions.

Version 19.2.7 (#36591)

Releasing with
```console
gh workflow run runtime_release_from_ci.yml \
  --ref releases/19.2.x \
  --raw-field="type=stable-latest"\
  --raw-field="only_packages=react react-art react-dom react-server-dom-webpack react-server-dom-turbopack react-server-dom-parcel react-is react-test-renderer" \
  --raw-field="dry=true"
```

Version 19.1.8 (#36590)

Releasing with
```console
gh workflow run runtime_release_from_ci.yml \
  --ref releases/19.1.x \
  --raw-field="type=stable-backport"\
  --raw-field="only_packages=react react-art react-dom react-server-dom-webpack react-server-dom-turbopack react-server-dom-parcel react-is react-test-renderer" \
  --raw-field="dry=true"
```

Version 19.0.7 (#36589)

Releasing with
```console
gh workflow run runtime_release_from_ci.yml \
  --ref releases/19.0.x \
  --raw-field="type=stable-backport"\
  --raw-field="only_packages=react react-art react-dom react-server-dom-webpack react-server-dom-turbopack react-is react-test-renderer" \
  --raw-field="dry=true"
```