[Bugfix] avoid deadlock caused by android.bg and RollbackManagerServiceHandler

android.bg is waiting for RollbackManagerServiceHandler to complete the actual code logic of getAvailableRollbacks, but RollbackManagerServiceHandler is waiting for the lock held by android.bg when running to PackageWatchdog.dump().
PackageWatchdog.dump() needs to be moved outside awaitResult().

Bug: 318782981
Test: Manual test
Change-Id: Ibb23567401eea16567f9f68f97badfdaeff1fc27
Signed-off-by: panhaihui <panhaihui@xiaomi.com>