Make com.facebook.react.views.common.ContextUtils internal (#51959)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/51959

This class is public while it should not. It's just internal utilities which we don't really want to expose to 3p users.

I've noticed only one unmaintained libraries (3 year old) that will be affected by this change: https://github.com/phanithken/react-native-pk-image-picker/blob/3c21d0e8e3a797d73806883041500fd546e427d6/android/src/main/java/com/pkimagepicker/PkImagePickerViewHost.kt#L63
So I'm marking this as not breaking.

Changelog:
[Android] [Changed] - Make com.facebook.react.views.common.ContextUtils internal

Reviewed By: alanleedev

Differential Revision: D76429746

fbshipit-source-id: 1677a4b7ae7f2cc2c6c941e7e5fe89a5b332fa20