Add a periodic check of the tethering provisioning

Add a service that handles the check through broadcasts which are
defined through configs, similar to the previous configs for the
activity.

Depends on I1f6e2d954562c5a16a0de60dac625005ec3e5c50

Bug: 18453076
Change-Id: I515d72706e9ca37877e67c44427af1b75b146390

src/com/android/settings/HotspotOffReceiver.java

@@ -0,0 +1,25 @@
+
+package com.android.settings;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.net.wifi.WifiManager;
+
+/**
+ * This receiver catches when quick settings turns off the hotspot, so we can
+ * cancel the alarm in that case.  All other cancels are handled in tethersettings.
+ */
+public class HotspotOffReceiver extends BroadcastReceiver {
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        if (WifiManager.WIFI_AP_STATE_CHANGED_ACTION.equals(intent.getAction())) {
+            WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
+            if (wifiManager.getWifiApState() == WifiManager.WIFI_AP_STATE_DISABLED) {
+                // The hotspot has been turned off, we don't need to recheck tethering.
+                TetherService.cancelRecheckAlarmIfNecessary(context, TetherSettings.WIFI_TETHERING);
+            }
+        }
+    }
+}