Re-enable integration tests (#46639)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46639

These tests were skipped when we were switching to component stacks, which also hid a bug later in the stack. Re-enable them.

Changelog: [Internal]

Reviewed By: javache

Differential Revision: D63349616

fbshipit-source-id: ccde7d5bb3fcd9a27adf4af2068a160f02f7432a