Bug 1402358 - In Android emulator tests, shutdown faster; r=jmaher

When the emulator is in good shape, emulator verification on shutdown
only takes a few seconds. However, if the emulator is hung or otherwise
unresponsive, emulator verification can take several minutes. In the
pathological worst case, verification slows down the task enough to
exceed the task timeout, resulting in a failure that would otherwise
have been handled as a task retry. Emulator verification on shutdown
provides little value, so it is simply eliminated.

testing/mozharness/scripts/android_emulator_unittest.py

@@ -830,9 +830,8 @@ class AndroidEmulatorTest(TestingMixin, EmulatorMixin, BaseScript, MozbaseMixin)
     @PostScriptAction('run-tests')
     def stop_emulator(self, action, success=None):
         '''
-        Report emulator health, then make sure that the emulator has been stopped
+        Make sure that the emulator has been stopped
         '''
-        self._verify_emulator()
         self._kill_processes(self.config["emulator_process_name"])