private static void cacheDeviceAdminComponent(final Context context) {
		if (sCachedComponent == null) sCachedComponent = DeviceAdmins.getComponentName(context);
	}
@see DevicePolicyManager#addCrossProfileIntentFilter(ComponentName, IntentFilter, int)
shared/src/main/java/com/oasisfeng/island/util/DevicePolicies.java