Check if isInstalled() when boot completed

When the service receives BOOT_COMPLETED, check not only isInUse(),
but also isInstalled(). If there is already an AOT installed, notify
the user and provide a action button to discard it, or reboot into it
again.

Bug: 126377329
Test: install AOT and reboot.
Change-Id: Ib764524bc755380164dab920c8946247757dde20