Pilfer pointers when touch gesture transferred to embedded.

Once the touch gesture transferred to embedded window, the host
activity won't receive motion event, instead the event will dispatch
to embedded process. In that scenario the remote process must not
receive motion event since there is no DecorView to intercept for back
animation callback.
Also disable send motion events if the client app was register normal
OnBackInvokedCallback, since it does not have to handle back progress.

Flag: com.android.window.flags.disallow_app_progress_embedded_window
Bug: 365504126
Test: Test on sample app, once touch gesture transfer to embedded
process, the remote process must not receive motion event when back
gesture start as soon as possible.

Change-Id: I712bab3c2b0de6a0960acac61dfca81341a7f543