Fix MSIME client's active state

Introduce per-display active client. Also, deactivate previous client
when window loses focus so that connection can be restarted on next
focus gain.

Test: Manually using the steps in bug.
Bug: 131619304
Change-Id: Iefad3f018ef0cc1b3729af4a140afa1b52139ce0
Merged-In: Iefad3f018ef0cc1b3729af4a140afa1b52139ce0
2 files changed