protect OTASP service with modify phone state permssion

protect the service with permissions so that it won't be started by
any unprivileged users/apps

Bug: 115898693
Test: Manaul & Build
Change-Id: I11d49989fe447e2281dfb727603739a5aa18fa43
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index ce774d8..6138c9b 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -393,7 +393,8 @@
 
         <!-- Activation service that trigger OTASP sim provisioning -->
         <service android:name=".otasp.OtaspActivationService" android:launchMode="singleInstance"
-                 androidprv:systemUserOnly="true">
+            androidprv:systemUserOnly="true"
+            android:permission="android.permission.MODIFY_PHONE_STATE">
             <intent-filter>
                 <action android:name="android.service.simActivation.SimActivationService" />
             </intent-filter>