add CF_MEDIA_PAUSE channel flag to allow waiting for IO before media codec is ready

This could be used at endpoints where signalling and media negotiated separately like in H323

src/include/switch_types.h

@@ -1362,6 +1362,7 @@ typedef enum {
 	CF_VIDEO_ECHO,
 	CF_SLA_INTERCEPT,
 	CF_VIDEO_BREAK,
+	CF_MEDIA_PAUSE,
 	/* WARNING: DO NOT ADD ANY FLAGS BELOW THIS LINE */
 	/* IF YOU ADD NEW ONES CHECK IF THEY SHOULD PERSIST OR ZERO THEM IN switch_core_session.c switch_core_session_request_xml() */
 	CF_FLAG_MAX