Prepare to support fade seamless rotation

Previously, the effect is exclusive.
ACTION_SEAMLESS: jump-cut with new rotation.
ACTION_FADE: fade out with old rotation and fade in with new rotation.

Now it can utilize ACTION_SEAMLESS | ACTION_FADE for non-activity
windows to have smoother seamless transition. The ACTION_SEAMLESS
can make sure the fade animation run in consistent rotation even
if display rotation change has applied.

This CL doesn't have behavior change because the actions are still
set exclusively.

Bug: 399452199
Flag: EXEMPT refactor
Test: DisplayContentTests#testShellTransitRotation

Change-Id: Ia65fd2fbb4cc5de2b5ce5db99eafef5c251611f6