Identify and fix potential thread safety issues in SplitController
1) Went through SplitController call paths
2) Some methods require locks and were not annotated. Checked the call
paths for these methods, ensured callers had acquired the lock
somewhere up the chain, and added GuardedBy to these methods
3) Fixed unsafe area(s):
A) onStartActivityResult accesses #getContainer, which iterates
through mTaskContainers, which requires a lock. Updated the
onStartActivityResult block to use a lock
Bug: 242647030
Test: make androidx.window.extensions RUN_ERROR_PRONE=true
check warnings
Test: Smoke test with Jetpack WindowManager Demos apk
Change-Id: I1099cf76f88e49c706b65e394afbb82dd4a1bb99
3 files changed