Add a hidden API to toggle airplane mode.

Added a hidden API under ConnectivityManager to toggle airplane mode.
This may be a temp solution for b/10653570.
bug:10653570

Change-Id: I0b2b42230073289eb8dc6891317d62b84e26c133

services/java/com/android/server/ConnectivityService.java

@@ -4681,6 +4681,21 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         setProvNotificationVisible(visible, networkType, extraInfo, url);
     }
 
+    @Override
+    public void setAirplaneMode(boolean enable) {
+        enforceConnectivityInternalPermission();
+        final ContentResolver cr = mContext.getContentResolver();
+        Settings.Global.putInt(cr, Settings.Global.AIRPLANE_MODE_ON, enable ? 1 : 0);
+        Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
+        intent.putExtra("state", enable);
+        final long ident = Binder.clearCallingIdentity();
+        try {
+            mContext.sendBroadcast(intent);
+        } finally {
+            Binder.restoreCallingIdentity(ident);
+        }
+    }
+
     private void onUserStart(int userId) {
         synchronized(mVpns) {
             Vpn userVpn = mVpns.get(userId);