Add in sandbox UIDs when configuring VPN.

SDK sandboxes that belong to an application should follow the same VPN
configuration that their corresponding app does.

Bug: 225317905
Test: atest VpnTest
Change-Id: I634f47a013fa2e42908d963fcd0634778298fee5

services/core/java/com/android/server/connectivity/Vpn.java

@@ -1533,11 +1533,17 @@ public class Vpn {
     }
 
     // Note: Return type guarantees results are deduped and sorted, which callers require.
+    // This method also adds the SDK sandbox UIDs corresponding to the applications by default,
+    // since apps are generally not aware of them, yet they should follow the VPN configuration
+    // of the app they belong to.
     private SortedSet<Integer> getAppsUids(List<String> packageNames, int userId) {
         SortedSet<Integer> uids = new TreeSet<>();
         for (String app : packageNames) {
             int uid = getAppUid(app, userId);
             if (uid != -1) uids.add(uid);
+            if (Process.isApplicationUid(uid)) {
+                uids.add(Process.toSdkSandboxUid(uid));
+            }
         }
         return uids;
     }