settings: add back all keyboard IME features back (2/2)

this commit adds:

- ime switcher notification - thanks cm
- fullscreen disable on landscape
- force autorotation on IME
- volume button control for navigate in the message - thanks cm
- force to show always enter key

some fixes to the 4.2/4.3 implementations + added full multiuser
support for all this features
Merge branch 'kk4.4' of github.com:TEAM-Gummy/android_packages_apps_Settings into kk4.4