Add Carriers.APN_SET_ID and NO_SET_SET

Add them as hidden for now.

Bug: 70172263
Test: TelephonyProviderTest#testApnSetId
Change-Id: Id16dd5631d327f403a7347b72ecfb27a5e298541

telephony/java/android/provider/Telephony.java

@@ -2900,12 +2900,30 @@ public final class Telephony {
          * @hide
          */
         public static final int OWNED_BY_DPC = 0;
+
         /**
          * Possible value for the OWNED_BY field.
          * APN is owned by other sources.
          * @hide
          */
         public static final int OWNED_BY_OTHERS = 1;
+
+        /**
+         * The APN set id. When the user manually selects an APN or the framework sets an APN as
+         * preferred, all APNs with the same set id as the selected APN should be prioritized over
+         * APNs in other sets.
+         * @hide
+         */
+        public static final String APN_SET_ID = "apn_set_id";
+
+        /**
+         * Possible value for the APN_SET_ID field. By default APNs will not belong to a set. If the
+         * user manually selects an APN with no set set, there is no need to prioritize any specific
+         * APN set ids.
+         * @hide
+         */
+        public static final int NO_SET_SET = 0;
+
     }
 
     /**