Fix potential failures in InputMethodService

It had the chance for calling into IMS but IMS
already destroyed.

Ideally we should suppress any callbacks after
InputMethodService#onDestroy() and log them.

Bug: 121269861
Bug: 211062619
Bug: 148086656
Test: presubmit
Change-Id: I10f26a92e739b60c5b8010e8476f8f5a403e0a7b