Refine the APIs of system bar appearance/behavior:
- Add getters
- Let the caller can only change certain appearance flags with out
touching others
- Adjust appearance/behavior for the legacy apps if they don't uses the
new APIs
Bug: 118118435
Test: atest InsetsSourceProviderTest InsetsStateControllerTest
InsetsPolicyTest WindowStateTests CommandQueueTest
RegisterStatusBarResultTest InsetsFlagsTest
LightBarControllerTest RegisterStatusBarResultTest
ViewRootImplTest DisplayPolicyLayoutTests
DisplayPolicyInsetsTests DisplayPolicyTests
TaskSnapshotSurfaceTest
Change-Id: I388decc9dc9b617348a6352b81fe77a19f27a0d7
7238a059c0