Fix usagestats DUMP OF SERVICE

DUMP OF SERVICE Usagestats was empty in bugreports
because an unexpected -a argument was being passed.
adb shell pm dump <package> had a similar issue with --packages

Change-Id: Ic67c723b8edc74ec7c9c48582b08896ca3430a4a
Fix: 70777338
Test: adb shell pm dump <package> and bugreports now contain usage stats