Updates to coroutine tracing

 - Small performance improvements

 - New tests

 - New comments

 - Fix issue with concurrent modification of TraceData that would
   cause malformed traces

Flag: ACONFIG com.android.systemui.coroutine_tracing DEVELOPMENT
Bug: 289353932
Test: atest tracinglib-host-test tracinglib-robolectric-test
Change-Id: I08e3b492db36f4a9c02af17587624b2740f83d30
6 files changed