[VCN12] Expose setSubIds/getSubIds APIs

Test: atest NetworkCapabilitiesTest
Bug: 175662146
Change-Id: Ia4b98bc6c5fcefee44233f3b7fbb6517a0e8870e

framework/src/android/net/NetworkCapabilities.java

@@ -2284,7 +2284,6 @@ public final class NetworkCapabilities implements Parcelable {
 
     /**
      * Gets the subscription ID set that associated to this network or request.
-     * @hide
      * @return
      */
     @NonNull
@@ -2637,8 +2636,6 @@ public final class NetworkCapabilities implements Parcelable {
          *
          * @param subIds a set that represent the subscription IDs. Empty if clean up.
          * @return this builder.
-         *
-         * @hide
          */
         @NonNull
         public Builder setSubIds(@NonNull final Set<Integer> subIds) {

framework/src/android/net/NetworkRequest.java

@@ -465,8 +465,6 @@ public class NetworkRequest implements Parcelable {
          * An empty set matches all networks, including those without a subId.
          *
          * @param subIds A {@code Set} that represents subscription IDs.
-         *
-         * @hide
          */
         @NonNull
         public Builder setSubIds(@NonNull Set<Integer> subIds) {