Don't expose raw IBinder APIs.

APIs should not expose raw IBinder objects.

Fix: 184735751
Test: builds, boots
Test: atest CtsNetTestCases:android.net.cts.ConnectivityManagerTest
Test: atest CtsNetTestCases:android.net.cts.DnsResolverTest
Change-Id: Ia0c4170def31123f0b79318fec2cfe02e4fcd3bf

framework/src/android/net/DnsResolverServiceManager.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.net;
+
+import android.annotation.NonNull;
+import android.os.IBinder;
+
+/**
+ * Provides a way to obtain the DnsResolver binder objects.
+ *
+ * @hide
+ */
+public class DnsResolverServiceManager {
+    /** Service name for the DNS resolver. Keep in sync with DnsResolverService.h */
+    public static final String DNS_RESOLVER_SERVICE = "dnsresolver";
+
+    private final IBinder mResolver;
+
+    DnsResolverServiceManager(IBinder resolver) {
+        mResolver = resolver;
+    }
+
+    /**
+     * Get an {@link IBinder} representing the DnsResolver stable AIDL interface
+     *
+     * @return {@link android.net.IDnsResolver} IBinder.
+     */
+    @NonNull
+    public IBinder getService() {
+        return mResolver;
+    }
+}