Fix NetworkOffer Death link does not exist am: 3ec7e6d9fb am: f405adead7 am: a5208a6aa2

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1799528

Change-Id: Id307e54a38054207ae164851c86bed1314ef7a2b

service/src/com/android/server/ConnectivityService.java

@@ -6908,7 +6908,11 @@ public class ConnectivityService extends IConnectivityManager.Stub
         if (DBG) {
             log("unregister offer from providerId " + noi.offer.providerId + " : " + noi.offer);
         }
-        mNetworkOffers.remove(noi);
+
+        // If the provider removes the offer and dies immediately afterwards this
+        // function may be called twice in a row, but the array will no longer contain
+        // the offer.
+        if (!mNetworkOffers.remove(noi)) return;
         noi.offer.callback.asBinder().unlinkToDeath(noi, 0 /* flags */);
     }