Fix crash in ViewManagerPropertyProcessor on older android devices (#45303)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/45303

`ViewManagersPropertyCache` uses reflection to find all ReactProp but fails when any symbols in the method refer to classes not available in the current build.

Work around this by extracting this helper to a separate private inner class.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D59397865

fbshipit-source-id: e77d3167698e4311e8778ebab28a0c8a0d2666c2