Set maximum group name

Closes #3438

res/layout/group_create_activity.xml

@@ -35,6 +35,7 @@
                 android:layout_gravity="center_vertical"
                 android:padding="10dp"
                 android:lines="1"
+                android:maxLength="255"
                 android:inputType="textAutoCorrect"
                 android:hint="@string/GroupCreateActivity_group_name_hint" />
             </LinearLayout>
@@ -98,4 +99,4 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content" />
 
-</LinearLayout>
+</LinearLayout>