AndroidDevice: fixing UI hierarchy capture

- renamed the capture method from "capture_view_hierachy" to
  "capture_ui_hierarchy" to fix typo and make more descriptive.
- Change the file extension of the cature file to ".uix" because this is
  the extension uiautomatorviewer looks for.

wlauto/common/android/device.py

@@ -619,7 +619,7 @@ class AndroidDevice(BaseLinuxDevice):  # pylint: disable=W0223
         self.pull_file(on_device_file, filepath)
         self.delete_file(on_device_file)
 
-    def capture_view_hierachy(self, filepath):
+    def capture_ui_hierarchy(self, filepath):
         """Captures the current view hierarchy into the specified file in a XML format."""
         on_device_file = self.path.join(self.working_directory, 'screen_capture.xml')
         self.execute('uiautomator dump {}'.format(on_device_file))

wlauto/core/execution.py

@@ -742,7 +742,7 @@ class Runner(object):
             filepath = os.path.join(self.context.output_directory, filename)
         else:
             filepath = os.path.join(settings.output_directory, filename)
-        self.device.capture_view_hierachy(filepath)
+        self.device.capture_ui_hierarchy(filepath)
 
     @contextmanager
     def _handle_errors(self, action, on_error_status=IterationResult.FAILED):
@@ -764,7 +764,7 @@ class Runner(object):
                 try:
                     self._take_screenshot('error.png')
                     if self.device.platform == 'android':
-                        self._take_uiautomator_dump('error.xml')
+                        self._take_uiautomator_dump('error.uix')
                 except Exception, e:  # pylint: disable=W0703
                     # We're already in error state, so the fact that taking a
                     # screenshot failed is not surprising...