Revert "Only check ALPN if TLS extensions are enabled"

This reverts commit 5fb58fe.

Author: megla-tlanghorst

okhttp/src/main/java/io/grpc/okhttp/TlsServerHandshakerSocketFactory.java

@@ -55,16 +55,13 @@ public HandshakeResult handshake(Socket socket, Attributes attributes) throws IO
     SSLSocket sslSocket = (SSLSocket) socket;
     sslSocket.setUseClientMode(false);
     connectionSpec.apply(sslSocket, false);
-    if (connectionSpec.supportsTlsExtensions()) {
-      Protocol expectedProtocol = Protocol.HTTP_2;
-      String negotiatedProtocol = OkHttpProtocolNegotiator.get().negotiate(
-          sslSocket,
-          null,
-          Collections.singletonList(expectedProtocol)
-      );
-      if (!expectedProtocol.toString().equals(negotiatedProtocol)) {
-        throw new IOException("Expected NPN/ALPN " + expectedProtocol + ": " + negotiatedProtocol);
-      }
+    Protocol expectedProtocol = Protocol.HTTP_2;
+    String negotiatedProtocol = OkHttpProtocolNegotiator.get().negotiate(
+        sslSocket,
+        null,
+        connectionSpec.supportsTlsExtensions() ? Collections.singletonList(expectedProtocol) : null);
+    if (!expectedProtocol.toString().equals(negotiatedProtocol)) {
+      throw new IOException("Expected NPN/ALPN " + expectedProtocol + ": " + negotiatedProtocol);
     }
     attributes = result.attributes.toBuilder()
         .set(GrpcAttributes.ATTR_SECURITY_LEVEL, SecurityLevel.PRIVACY_AND_INTEGRITY)