Decouple OverViewProxyService from DividerView

Add registerBoundsChangeListener API to let others register split screen
bounds chagne listener to decouple OverViewProxyService from DividerView.

Bug: 161116823
Test: atest SystemUITests
Test: manual check splitscreen and recents behavior
Change-Id: I25d0bfaa8c044a91266c35d977bcfba76e8d1c24
4 files changed