Remove IMMS#MSG_INITIALIZE_IME

This CL inlines

  InputMethodManagerService#MSG_INITIALIZE_IME

handler as it has always been executed from the calling thread.

There should be no observable behavior change.

Bug: 215609403
Test: presubmit
Change-Id: If2806df9cef00cbe7612085b6afa7800f5d9d930
2 files changed