Remove protected-broadcast declaration of IKE intents

After Android U, the Iwlan service runs with an non-privileged UID. That
is, protected-broadcast intents cannot be sent to the Iwlan service.
Therefore, remove the protected-broadcast declaration for the following
IKE intents.

- IkeAlarmReceiver.ACTION_DELETE_CHILD
- IkeAlarmReceiver.ACTION_REKEY_CHILD
- IkeAlarmReceiver.ACTION_DELETE_IKE
- IkeAlarmReceiver.ACTION_REKEY_IKE
- IkeAlarmReceiver.ACTION_DPD
- IkeAlarmReceiver.ACTION_KEEPALIVE

Bug: 251078463
Test: on-device regression test
Change-Id: I14ad34f5781e5bdec0260fcef5ee86ba71d3b6c7
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 22bff6a..d4f541f 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -15,13 +15,6 @@
   <uses-permission android:name="android.permission.WAKE_LOCK" />
   <uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM" />
 
-  <protected-broadcast android:name="IkeAlarmReceiver.ACTION_DELETE_CHILD" />
-  <protected-broadcast android:name="IkeAlarmReceiver.ACTION_REKEY_CHILD" />
-  <protected-broadcast android:name="IkeAlarmReceiver.ACTION_DELETE_IKE" />
-  <protected-broadcast android:name="IkeAlarmReceiver.ACTION_REKEY_IKE" />
-  <protected-broadcast android:name="IkeAlarmReceiver.ACTION_DPD" />
-  <protected-broadcast android:name="IkeAlarmReceiver.ACTION_KEEPALIVE" />
-
   <application
       android:directBootAware="true"
       android:defaultToDeviceProtectedStorage="true">