Add fling velocity handling to cross task predictive back

Bug: 373811048
Test: Manual, i.e. analysing and verifying smoothness of screen recordings of cross task predictive back animation
Flag: com.android.window.flags.predictive_back_timestamp_api
Change-Id: I246e3d6317d90356cbcf20083c2e9a4bd937a61e
1 file changed