Prevent user from creating duplicate labels.

This isn't enforced at the data layer just in the UI's that
allow editting of the group name.

Bug 28718604
Change-Id: I969b0298bd895fdbdd7f8609da05f2b801707c0a
diff --git a/res/layout/group_name_edit_dialog.xml b/res/layout/group_name_edit_dialog.xml
index 9a8c69f..5df8c9d 100644
--- a/res/layout/group_name_edit_dialog.xml
+++ b/res/layout/group_name_edit_dialog.xml
@@ -14,24 +14,28 @@
      limitations under the License.
 -->
 
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<android.support.design.widget.TextInputLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/text_input_layout"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:orientation="vertical"
-    android:paddingBottom="24dp"
+    android:paddingEnd="24dp"
     android:paddingStart="24dp"
-    android:paddingEnd="24dp">
+    app:errorEnabled="true"
+    app:hintEnabled="false">
 
-    <EditText android:id="@android:id/text1"
-        xmlns:android="http://schemas.android.com/apk/res/android"
+    <android.support.design.widget.TextInputEditText
+        android:id="@android:id/text1"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:minHeight="@dimen/group_name_edit_text_min_height"
         android:layout_marginBottom="4dp"
         android:layout_marginRight="4dp"
         android:layout_marginTop="16dp"
         android:hint="@string/group_name_dialog_hint"
         android:inputType="text"
-        android:singleLine="true"
-        android:maxLength="@integer/group_name_max_length"/>
-</LinearLayout>
\ No newline at end of file
+        android:maxLength="@integer/group_name_max_length"
+        android:minHeight="@dimen/group_name_edit_text_min_height"
+        android:singleLine="true"/>
+</android.support.design.widget.TextInputLayout>
\ No newline at end of file