Let the activity embedded in ActivityView can be directly touched

The goal is to eliminate the latency caused by forwarding the event.

In this CL, we put an input portal window behind an ActivityView, and
subtract the touchable region of the the ActivityView, so that the user
can touch through the portal window, and let the touch arrive on the
embedded activity.

Bug: 120675821
Test: Manual test with ActivityViewTest
Test: atest CtsActivityManagerDeviceTestCases:ActivityViewTest
Change-Id: I6776387b65cf6a7d2ea60cb00ffdd38be22081ac