Move QoS API classes to Connectivity

The classes were added in S and are used to back ConnectivityManager
APIs. Add them to the connectivity boundary as they belong together with
ConnectivityManager.

Bug: 181512874
Test: m
Change-Id: I03b5978949b200a72813d1ebc4812d851fe3df37

framework/src/android/net/QosSessionAttributes.java

@@ -0,0 +1,30 @@
+/*
+ * 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.SystemApi;
+
+/**
+ * Implemented by classes that encapsulate Qos related attributes that describe a Qos Session.
+ *
+ * Use the instanceof keyword to determine the underlying type.
+ *
+ * @hide
+ */
+@SystemApi
+public interface QosSessionAttributes {
+}