Update transport interface to remove const qualifier from NetworkContext_t * in send/recv (#356)

This removes a warning involving const qualifiers. The NetworkContext_t * cannot be declared as const in TransportRecv and TransportSend because mbedtls_ssl_write and mbedtls_ssl_read require non-const pointers. Therefore, the const qualifier is removed from transport_interface.h.

FreeRTOS-Plus/Source/Application-Protocols/platform/include/transport_interface.h

@@ -165,7 +165,7 @@ typedef struct NetworkContext NetworkContext_t;
  * @return The number of bytes received or a negative error code.
  */
 /* @[define_transportrecv] */
-typedef int32_t ( * TransportRecv_t )( const NetworkContext_t * pNetworkContext,
+typedef int32_t ( * TransportRecv_t )( NetworkContext_t * pNetworkContext,
                                        void * pBuffer,
                                        size_t bytesToRecv );
 /* @[define_transportrecv] */
@@ -181,7 +181,7 @@ typedef int32_t ( * TransportRecv_t )( const NetworkContext_t * pNetworkContext,
  * @return The number of bytes sent or a negative error code.
  */
 /* @[define_transportsend] */
-typedef int32_t ( * TransportSend_t )( const NetworkContext_t * pNetworkContext,
+typedef int32_t ( * TransportSend_t )( NetworkContext_t * pNetworkContext,
                                        const void * pBuffer,
                                        size_t bytesToSend );
 /* @[define_transportsend] */