Dwayne Johnson, left, and Dany Garcia. Photographer: Kevin Mazur/Eric Umphrey via Acorns Photographer: Kevin Mazur/Eric Umphrey via Acorns Dwayne “The Rock” Johnson and his business partner Dany Garcia are making a investment in digital personal-finance service Acorns — which will give each new user a $7 credit, a symbolic reference […]