By Jelani Scott The league and players association announced the findings of an investigation into the Dolphins quarterback’s injury against the Bills. The NFL followed through on its plan to modify concussion protocols Saturday with the announcement of modified guidelines that will go into effect when Week 5 resumes this Sunday. The landmark news coincided with a statement from the NFL and players association announcing the findings of the now-completed investigation into the Dolphins’ handling of Tua Tagovailoa’s concussion check in Week 3. Less than a week into that investigation, the NFLPA…