Adding Tethering proto

Bug: 153942334
Test: m, flash and boot
Change-Id: I853d3a4dd914dd0c65a6c9e1749d8898da68540e

Tethering/Android.bp

@@ -47,6 +47,7 @@ java_defaults {
         "net-utils-device-common-bpf",
         "net-utils-device-common-netlink",
         "netd-client",
+        "tetheringstatsprotos",
     ],
     libs: [
         "framework-connectivity",
@@ -211,3 +212,14 @@ sdk {
     bootclasspath_fragments: ["com.android.tethering-bootclasspath-fragment"],
     systemserverclasspath_fragments: ["com.android.tethering-systemserverclasspath-fragment"],
 }
+
+java_library_static {
+    name: "tetheringstatsprotos",
+    proto: {type: "lite"},
+    srcs: [
+        "src/com/android/networkstack/tethering/metrics/stats.proto",
+    ],
+    static_libs: ["tetheringprotos"],
+    apex_available: ["com.android.tethering"],
+    min_sdk_version: "30",
+}

Tethering/jarjar-rules.txt

@@ -12,3 +12,5 @@ rule com.android.net.module.util.** com.android.networkstack.tethering.util.@1
 
 # Classes from net-utils-device-common
 rule com.android.net.module.util.Struct* com.android.networkstack.tethering.util.Struct@1
+
+rule com.google.protobuf.** com.android.networkstack.tethering.protobuf@1

Tethering/proguard.flags

@@ -19,3 +19,9 @@
 -keepclassmembers class android.net.ip.IpServer {
     static final int CMD_*;
 }
+
+# The lite proto runtime uses reflection to access fields based on the names in
+# the schema, keep all the fields.
+-keepclassmembers class * extends com.android.networkstack.tethering.protobuf.MessageLite {
+    <fields>;
+}

Tethering/src/com/android/networkstack/tethering/metrics/stats.proto

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+syntax = "proto2";
+option java_multiple_files = true;
+
+package com.android.networkstack.tethering.metrics;
+
+import "frameworks/proto_logging/stats/enums/stats/connectivity/tethering.proto";
+
+/**
+ * Logs Tethering events
+ */
+message NetworkTetheringReported {
+   optional .android.stats.connectivity.ErrorCode error_code = 1;
+   optional .android.stats.connectivity.DownstreamType downstream_type = 2;
+   optional .android.stats.connectivity.UpstreamType upstream_type = 3;
+   optional .android.stats.connectivity.UserType user_type = 4;
+}