fix: remove appended dot in waitactivity (#383)

Remove appending of dot in Android wait_activity

copying from: #169

Author: euphonious28

AppiumLibrary/keywords/_android_utils.py

@@ -163,10 +163,6 @@ def wait_activity(self, activity, timeout, interval=1):
          - _timeout_ - max wait time, in seconds
          - _interval_ - sleep interval between retries, in seconds
         """
-
-        if not activity.startswith('.'):
-            activity = ".%s" % activity
-
         driver = self._current_application()
         if not driver.wait_activity(activity=activity, timeout=float(timeout), interval=float(interval)):
             raise TimeoutException(msg="Activity %s never presented, current activity: %s" % (activity, self.get_activity()))