ethernet: provider to keep track of requestId

Keeping track of request ids instead of the entire NetworkRequest is
slightly more efficient.

Per suggestion in aosp/2059590.

Test: TH
Change-Id: I70c96a09d8f011d7b59852f2e9798154ee91c6d8
diff --git a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
index d5ec604..9834b18 100644
--- a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
+++ b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
@@ -300,7 +300,7 @@
         private boolean mLinkUp;
         private int mLegacyType;
         private LinkProperties mLinkProperties = new LinkProperties();
-        private Set<NetworkRequest> mRequests = new ArraySet<>();
+        private final Set<Integer> mRequestIds = new ArraySet<>();
 
         private volatile @Nullable IpClientManager mIpClient;
         private @NonNull NetworkCapabilities mCapabilities;
@@ -409,7 +409,7 @@
                 // existing requests.
                 // ConnectivityService filters requests for us based on the NetworkCapabilities
                 // passed in the registerNetworkOffer() call.
-                mRequests.add(request);
+                mRequestIds.add(request.requestId);
                 // if the network is already started, this is a no-op.
                 start();
             }
@@ -420,8 +420,12 @@
                     Log.d(TAG,
                             String.format("%s: onNetworkUnneeded for request: %s", name, request));
                 }
-                mRequests.remove(request);
-                if (mRequests.isEmpty()) {
+                if (!mRequestIds.remove(request.requestId)) {
+                    // This can only happen if onNetworkNeeded was not called for a request or if
+                    // the requestId changed. Both should *never* happen.
+                    Log.wtf(TAG, "onNetworkUnneeded called for unknown request");
+                }
+                if (mRequestIds.isEmpty()) {
                     // not currently serving any requests, stop the network.
                     stop();
                 }
@@ -671,7 +675,7 @@
         public void destroy() {
             mNetworkProvider.unregisterNetworkOffer(mNetworkOfferCallback);
             stop();
-            mRequests.clear();
+            mRequestIds.clear();
         }
 
         private static void provisionIpClient(@NonNull final IpClientManager ipClient,