Have a new library - netd-client in frameworks/libs/net

Move BaseNetdUnsolicitedEventListener from tethering module to
frameworks/libs/net and have a new library for it.
Tethering module can still use BaseNetdUnsolicitedEventListener
through netd-client and ConnectivityService and Nat464Xlat also
can use it when both of them are under frameworks/base.

Bug: 174837473
Test: Manual test and check the log.
Change-Id: I44dff1c7639e50b8f20b54c6d5733139b20e2986

staticlibs/client-libs/Android.bp

@@ -0,0 +1,19 @@
+java_library {
+    name: "netd-client",
+    srcs: ["netd/**/*"],
+    sdk_version: "system_current",
+    min_sdk_version: "29",
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.tethering"
+    ],
+    visibility: [
+        "//packages/modules/Connectivity/Tethering",
+        "//frameworks/base/services:__subpackages__"
+    ],
+    libs: ["androidx.annotation_annotation"],
+    static_libs: [
+        "netd_aidl_interface-java",
+        "netd_event_listener_interface-java"
+    ]
+}

staticlibs/client-libs/netd/com/android/net/module/util/BaseNetdUnsolicitedEventListener.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2019 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 com.android.net.module.util;
+
+import android.net.INetdUnsolicitedEventListener;
+
+import androidx.annotation.NonNull;
+
+/**
+ * Base {@link INetdUnsolicitedEventListener} that provides no-op implementations which can be
+ * overridden.
+ */
+public class BaseNetdUnsolicitedEventListener extends INetdUnsolicitedEventListener.Stub {
+
+    @Override
+    public void onInterfaceClassActivityChanged(boolean isActive, int timerLabel, long timestampNs,
+            int uid) { }
+
+    @Override
+    public void onQuotaLimitReached(@NonNull String alertName, @NonNull String ifName) { }
+
+    @Override
+    public void onInterfaceDnsServerInfo(@NonNull String ifName, long lifetimeS,
+            @NonNull String[] servers) { }
+
+    @Override
+    public void onInterfaceAddressUpdated(@NonNull String addr, String ifName, int flags,
+            int scope) { }
+
+    @Override
+    public void onInterfaceAddressRemoved(@NonNull String addr, @NonNull String ifName, int flags,
+            int scope) { }
+
+    @Override
+    public void onInterfaceAdded(@NonNull String ifName) { }
+
+    @Override
+    public void onInterfaceRemoved(@NonNull String ifName) { }
+
+    @Override
+    public void onInterfaceChanged(@NonNull String ifName, boolean up) { }
+
+    @Override
+    public void onInterfaceLinkStateChanged(@NonNull String ifName, boolean up) { }
+
+    @Override
+    public void onRouteChanged(boolean updated, @NonNull String route, @NonNull String gateway,
+            @NonNull String ifName) { }
+
+    @Override
+    public void onStrictCleartextDetected(int uid, @NonNull String hex) { }
+
+    @Override
+    public int getInterfaceVersion() {
+        return INetdUnsolicitedEventListener.VERSION;
+    }
+
+    @Override
+    public String getInterfaceHash() {
+        return INetdUnsolicitedEventListener.HASH;
+    }
+}