Fix NPE when handling unresponsive embedded windows

- The input target may not be a window state, but we still need to
  report the ANR for the process

Bug: 433055104
Flag: EXEMPT bugfix
Test: Introduce an excessive  artificial embedded window input handling
      delay and ensure ANRs are still fired
Change-Id: Ie68e71a6d12f8cf90f5bc8f13c4d98bc97a4bf1c