Transitions CUJ associate to animation thread

Fix: 404190067
Test: record perfetto trace, verify TASK_TO_TASK cuj is now in
wmshell.anim
Test: DefaultTransitionHandlerTest
Test: ShellTransitionTests
Flag: EXEMPT small change to instrumentation only

Change-Id: I679213fdb768eac5366299d224cd2fd1f5081cfa