ActivityManagerService: Allow openContentUri from vendor/system/product.

Apps should not have direct access to this entry point. Check that the
caller is a vendor, system, or product package.

Test: Ran PoC app and CtsMediaPlayerTestCases.
Bug: 236688380
(cherry picked from commit d0ba7467)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:e37820e47c383aecf9d1173a0676c27e6a59ce4f)
Merged-In: I0335496d28fa5fc3bfe1fecd4be90040b0b3687f
Change-Id: I0335496d28fa5fc3bfe1fecd4be90040b0b3687f