Revert "Add API for Custom IME Switcher button visibility"

Revert submission 29904508-custom-ime-switcher-visibility-api

Reason for revert: Droidmonitor created revert due to b/377538389. Will be verifying through ABTD before submission.

Reverted changes: /q/submissionid:29904508-custom-ime-switcher-visibility-api

Change-Id: I213fca551fd99130127054f2d56cfab514ecf7a1
3 files changed