Allow network stack UID caller to retrieve cell identity

For backwards compatibility, we allow phone, system UID to
access cell identity through getServiceState. Cell broadcast
service, which is used to be part of telephony, now is running
under network stack UID. We should consider network stack UID as
trustable components like system/telephony.

Fix: 157618105
Test: Manual
Change-Id: I9b2dfc778752e130f5c7e44c4b2e45b63ac6f918
(cherry picked from commit 56cfdd1)

telephony/common/android/telephony/LocationAccessPolicy.java

@@ -260,11 +260,12 @@ private static LocationPermissionResult checkAppLocationPermissionHelper(Context
     /** Check if location permissions have been granted */
     public static LocationPermissionResult checkLocationPermission(
             Context context, LocationPermissionQuery query) {
-        // Always allow the phone process and system server to access location. This avoid
-        // breaking legacy code that rely on public-facing APIs to access cell location, and
-        // it doesn't create an info leak risk because the cell location is stored in the phone
+        // Always allow the phone process, system server, and network stack to access location.
+        // This avoid breaking legacy code that rely on public-facing APIs to access cell location,
+        // and it doesn't create an info leak risk because the cell location is stored in the phone
         // process anyway, and the system server already has location access.
         if (query.callingUid == Process.PHONE_UID || query.callingUid == Process.SYSTEM_UID
+                || query.callingUid == Process.NETWORK_STACK_UID
                 || query.callingUid == Process.ROOT_UID) {
             return LocationPermissionResult.ALLOWED;
         }