[indirect-sender] log when preparing a message for indirect tx (#4002)
[indirect-sender] log when preparing a message for indirect tx (#4002)


chshu/openthread,abtink/openthread,bukepo/openthread,chshu/openthread,bukepo/openthread,lanyuwen/openthread,lanyuwen/openthread,openthread/openthread,srickardti/openthread,librasungirl/openthread,srickardti/openthread,srickardti/openthread,openthread/openthread,jwhui/openthread,librasungirl/openthread,lanyuwen/openthread,abtink/openthread,chshu/openthread,chshu/openthread,bukepo/openthread,openthread/openthread,turon/openthread,srickardti/openthread,librasungirl/openthread,openthread/openthread,jwhui/openthread,librasungirl/openthread,turon/openthread,bukepo/openthread,chshu/openthread,turon/openthread,jwhui/openthread,turon/openthread,jwhui/openthread,chshu/openthread,lanyuwen/openthread,lanyuwen/openthread,abtink/openthread,lanyuwen/openthread,abtink/openthread