[KV] Move KVBT to its own package

And related classes.

Test: atest RunFrameworksServicesRoboTests
Test: adb shell bmgr backupnow com.google.android.apps.backupapp
Test: 1. adb shell bmgr backup com.google.android.apps.backupapp
      2. adb shell bmgr run
Test adb shell cmd jobscheduler run -f android 20537

Change-Id: I1aba694786a4e2a5add5c388cd095700ade1ace9