Support QosCallback for UDP socket: Expose API&CTS

Expose API to use QoSCallback for UDP socket.
- Constructor of QosSocketInfo with DatagramSocket
- matchesProtocol(int protocol) in QosFilter
- Constructor of SocketNotConnectedException &
  SocketRemoteAddressChangedException
Add CTS test cases for exposed API.

Bug: 233292861
Test: atest CtsNetTestCases
Change-Id: I52ff881b71b31c0f97c08200cd811205c25fcb44
diff --git a/framework/src/android/net/SocketNotConnectedException.java b/framework/src/android/net/SocketNotConnectedException.java
index fa2a615..a6357c7 100644
--- a/framework/src/android/net/SocketNotConnectedException.java
+++ b/framework/src/android/net/SocketNotConnectedException.java
@@ -16,13 +16,18 @@
 
 package android.net;
 
+import android.annotation.SystemApi;
+
+import com.android.internal.annotations.VisibleForTesting;
+
 /**
  * Thrown when a previously bound socket becomes unbound.
  *
  * @hide
  */
+@SystemApi
 public class SocketNotConnectedException extends Exception {
-    /** @hide */
+    @VisibleForTesting
     public SocketNotConnectedException() {
         super("The socket is not connected");
     }