Fix UsbResolverActivity: SuperNotCalledException

Results in a quick crash of the systemui process when
called with out args. (error path skips super.onCreate)

Unfortunately, broadcast receivers are also registered
in #onCreate, but unregistered in #onStop. Since the
activity is created but not started, stop isn't called
resulting in a leaked receiver. Calling onStop() here
fixes this.

Bug: 201719995
Test: adb shell am start -n
      com.android.systemui/com.android.systemui.usb.UsbResolverActivity
Change-Id: Id76491fe4779df14e54969b9ab04ef2f772c293c