Rate limit calls from apps to reportKeepClearAreaChanged

Only allows keep clear area changes to be reported every 100ms.
Helpful to keep IPC from app to WindowManager to SystemUI lower during
animations, when Views marked as preferKeepClear change position a lot.

Bug: 226583836
Test: atest KeepClearRectsTests
Change-Id: I9f6c86c5345218c9ee40f50a74d4357dd4e94dc7