Move #mDeviceIdToShowIme to binding controller

This CL mechanically moves #mDeviceIdToShowIme from IMMS to
InputMethodBindingController without changing the semantics.

Bug: 305849394
Test: presubmit
Flag: EXEMPT refactor
Change-Id: Ifeb454c4852da342e6850cebe404340b5d06cd6c
2 files changed