Dispatch insets to client if mState is changed

Previous logic in onStateChanged notifies insetsChanged based on the
change of mLastDispatchedState, which can make us dispatch redundant
insets changes to the app.

In this CL, we only notifies insetsChanged if mState is really changed
in onStateChanged -- we use the final mState (after updateState and
applyLocalVisibilityOverride) to compare with the one before changing.

Fix: 161924448
Test: atest InsetsControllerTest WindowInsetsControllerTests
Test: Swipe up to home while IME open and see if there is any jank
Change-Id: Ia536cdf76805caa56ca1b6eaf2b3db83b6ecd94e