DO NOT MERGE: Remove requirement for optional system activity intents

We're regularizing the situation by making these intents formally
optional, i.e. documenting that callers of startActivity() must be
prepared for a no-such-activity result.

Bug: 68300743
Bug: 62201251
Bug: 69587018
Bug: 109897333
Fixes: 77282739
Test: atest CtsContentTestCases:.AvailableIntentsTest
Change-Id: I1d07020ca85cd4d8d75190d1a69691f8133c885c
1 file changed