Request VPN permissions on activation

Signed-off-by: Eric Kuck <eric@bluelinelabs.com>

app/src/main/res/layout/tunnel_detail_fragment.xml

@@ -5,12 +5,14 @@
 
     <data>
 
-        <import type="com.wireguard.android.fragment.TunnelController" />
-
         <import type="com.wireguard.android.model.Tunnel.State" />
 
         <import type="com.wireguard.android.util.ClipboardUtils" />
 
+        <variable
+            name="fragment"
+            type="com.wireguard.android.fragment.TunnelDetailFragment" />
+
         <variable
             name="tunnel"
             type="com.wireguard.android.model.Tunnel" />
@@ -63,7 +65,7 @@
                         android:layout_alignBaseline="@+id/interface_title"
                         android:layout_alignParentEnd="true"
                         app:checked="@{tunnel.state == State.UP}"
-                        app:onBeforeCheckedChanged="@{TunnelController::setTunnelState}" />
+                        app:onBeforeCheckedChanged="@{fragment::setTunnelState}" />
 
                     <TextView
                         android:id="@+id/interface_name_label"