Implement DisplayArea Animation/Transition for one handed (7/N)

1) Use updateHandler to handle MSG queue in background
2) The field mIsInOneHanded used to ensure start/stop event wait in queue
3) Only finishOffset() can update mIsInOneHanded to prevent race condition
4) Schedule offset used for normal case with animation
5) Offset immediately used for rotation case

Test: atest OneHandedAnimationControllerTest
Test: atest OneHandedDisplayAreaOrganizerTest
Test: atest OneHandedManagerImplTest
Test: atest OneHandedUITest
Test: atest OneHandedSettingsUtilTest
Test: atest SystemUITests
Test: atest DisplayAreaPolicyBuilderTest
Bug: 150747909

Change-Id: Ic3396626027afcb9eaa4e7554f8f94920854ca7c