Fix asan failure in MoqtTestMessage.

There was a memcpy where the src and dest regions overlapped. Replaced with memmove.

PiperOrigin-RevId: 804489691

quiche/quic/moqt/test_tools/moqt_test_message.h

diff --git a/quiche/quic/moqt/test_tools/moqt_test_message.h b/quiche/quic/moqt/test_tools/moqt_test_message.h
index f6954ed..bbee41e 100644
--- a/quiche/quic/moqt/test_tools/moqt_test_message.h
+++ b/quiche/quic/moqt/test_tools/moqt_test_message.h
@@ -499,7 +499,7 @@
       raw_packet_[2] = 0x23;  // adjust payload length (-17)
       raw_packet_[6] = 0x02;  // only two parameters
       // Move MoqtImplementation up in the packet.
-      memcpy(raw_packet_ + 9, raw_packet_ + 26, 29);
+      memmove(raw_packet_ + 9, raw_packet_ + 26, 29);
       SetWireImage(raw_packet_, sizeof(raw_packet_) - 17);
     } else {
       SetWireImage(raw_packet_, sizeof(raw_packet_));