Refactor for system helper overlay phase 1.

List of modules included in this CL:
account-helper
activity-helper
commands-helper
connectivity-helper
device-helper
permission-helper
user-helper

Test: make system-helpers -j40
Test: make AndroidBvtTests -j40
Test: make tv-sysui-app-helper -j40
Test: make TvSettingsTests -j40
Test: make TvSysUiTests -j40
Test: make tv-play-movies-app-helper -j40
Test: make leanback-app-helpers -j40
Test: make Power -j40
Test: make device-helper -j40

Change-Id: Ia543d81ada1dda2a28a39da28561cf8278d6d469