Compose overscroll gesture updates

Two changes for the latest Compose prototype:
1. Pass the identity of the underlying app to the Overscroll plugin.
2. Enable the Compose gesture over an app when there's a Recents extra
card plugin active (otherwise the current app won't count as the
rightmost one).

Some changes to the gesture:
- Angle decreased from 35° to 25° to remove overlap with
Assistant gesture
- Distance increased from 8 to 110 dp. 110 dp is 2x the Assistant
gesture and roughly the same as scrubbing into an app from Home.
- Fling detection added; uses same distance threshold, 110 dp.
- If a touch was recognized as another gesture, the touch will not be
reinterpreted as a Compose gesture, no matter what touch movement occurs
- Fixes issue where Assistant + Compose could both be triggered
- Fixes issue where scrubbing apps to the left, then back to the right,
would bring in Compose. i.e. if a touch down + touch movement starts
bringing in Assistant UI elements, then, the user moves their touch
below the Assistant angle, the Compose gesture will not start
being recognized
- Gesture length required for fling lowered from 110 dp to 40 dp, per
tuning with PM.

Bug: b/146508473
Change-Id: I414573d1a92684d1d992837a5f1df522346ec211