Cleaning up InputConsumers

- Log the pid and user handle for the client input consumer
- Pass token to WMS to ensure that it is notified when the client input
  consumer process is killed

Bug: 37309537
Test: android.server.am.ActivityManagerPinnedStackTests
Change-Id: I432d96b1f524ab34dbbad3eeb67d996abdd5f4ca
Signed-off-by: Winson Chung <winsonc@google.com>