Fix side button visibility tracking.

Previously one could e.g. get legacy menu button being visible in
certain scenarios, like this one:
- Open legacy app, e.g. CatLog
- Invoke IME
- Lock screen
- Unlock screen
- Result: Menu button visible in keyguard

Change-Id: Ia796f73ec995ea1cc34d38f8aefdbccda7be7565
frameworks: base: grammar fixes

props to  Boštjan Mejak for letting JIRA know.

JIRA issue: CYAN-4913

Change-Id: I09b742b1935b7ae5a2588ddc2c8c529e4bac0664
Allow translucent navigation bar in landscape mode.

Change-Id: I5388f3f8a34533624619714bacfba52f95fc6d85