Bug 1762948 - Log Android AVD path when not found. r=mhentges

Differential Revision: https://phabricator.services.mozilla.com/D142862

testing/mozbase/mozrunner/mozrunner/devices/android_device.py

@@ -652,6 +652,7 @@ class AndroidEmulator(object):
         if os.path.exists(self.avd_path):
             _log_debug("AVD found at %s" % self.avd_path)
             return True
+        _log_warning("Could not find AVD at %s" % self.avd_path)
         return False
 
     def start(self, gpu_arg=None):