Added permission check for setCellInfoListRate

Now the caller needs to have MODIFY_PHONE_STATE to call
this API.

Test: Manual
bug: 33815946
Change-Id: Ia2cf0de383572033c70b94ae71080ef35c3f443c
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 81e6abc..340ec3f 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -1681,6 +1681,7 @@
 
     @Override
     public void setCellInfoListRate(int rateInMillis) {
+        enforceModifyPermission();
         WorkSource workSource = getWorkSource(null, Binder.getCallingUid());
         mPhone.setCellInfoListRate(rateInMillis, workSource);
     }