Show a button to disconnect the VPN once it is established

src/frontends/android/res/layout/vpn_state_fragment.xml

@@ -72,6 +72,17 @@
         </TextView>
     </GridLayout>
 
+    <Button
+        android:id="@+id/action"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="10dp"
+        android:layout_marginLeft="20dp"
+        android:layout_marginRight="20dp"
+        android:text="@string/disconnect"
+        style="?android:attr/borderlessButtonStyle" >
+    </Button>
+
     <View
         android:layout_width="match_parent"
         android:layout_height="2dp"

src/frontends/android/res/values/strings.xml

@@ -53,6 +53,7 @@
     <!-- VPN state fragment -->
     <string name="state_label">Status:</string>
     <string name="profile_label">Profile:</string>
+    <string name="disconnect">Disconnect</string>
     <string name="state_connecting">Connecting&#8230;</string>
     <string name="state_connected">Connected</string>
     <string name="state_disconnecting">Disconnecting&#8230;</string>