SyncPointerCapture (6/n): Move Pointer Capture to InputDispatcher

This CL relays requests to enable or disable Pointer Capture in
InputManagerService to InputDispatcher.

Windows now request Pointer Capture using their InputChannel token
instead of their IWindow tokens.

Bug: 141749603
Test: manual: flash crosshatch, test pointer capture.

Change-Id: Ic6fc01eae0068dfbba496051d988a71bcabcd0b3