workloads/gmail: Fix to use passed working directory parameter

In devlib the default working directory has changed causing the workload
to look in the wrong directory, now the workload should use the passed
working directory and extract the relevant name from there.

wa/workloads/gmail/__init__.py

@@ -65,6 +65,10 @@ class Gmail(ApkUiautoWorkload):
         super(Gmail, self).init_resources(context)
         if self.target.get_sdk_version() >= 24 and 'com.google.android.apps.photos' not in self.target.list_packages():
             raise WorkloadError('gmail workload requires Google Photos to be installed for Android N onwards')
+        # Allows for getting working directory regardless if path ends with a '/'
+        work_dir = self.target.working_directory
+        work_dir = work_dir if work_dir[-1] != os.sep else work_dir[:-1]
+        self.gui.uiauto_params['workdir_name'] = self.target.path.basename(work_dir)
         self.gui.uiauto_params['recipient'] = self.recipient
         # Only accept certain image formats
         if os.path.splitext(self.test_image.lower())[1] not in ['.jpg', '.jpeg', '.png']: