[Ambient Touch] Rework input dispatch policies during ambient mode.

1. Simplify wear's special logic in
   shouldDispatchInputWhenNonInteractive().
2. Always pass wakeful motion events to apps during ambient mode.

Test: atest CtsInputTestCases
Test: atest WmTests:PhoneWindowManagerTests
Test: Touch events during ambient mode is received by apps.
Test: Touch events during screen off is not received by apps.
Bug: 270228430
Change-Id: I7ccd0b33f762671f0433d112e9a41397c843dd04