Honor app visibility when get MIME type from ContentProvider

APIs getProviderMimeType and getProviderMimeTypeAsync from Activity-
ManagerService don't check whether the ContentProvider holder of the
given URI is visible to the callers.

Bug: 185126503
Bug: 185126713
Test: atest CtsContentTestCases
Test: atest CtsProviderTestCases
Test: manually using the PoC in the buganizer to ensure the symptom
      no longer exists.
Change-Id: I73427c7909f56e51d7aabeebb1bfa841b5fd6ffe