[diag] send frames only from the alarm handler in repeat mode (#4343)
[diag] send frames only from the alarm handler in repeat mode (#4343)

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