5v5 and 3v3 omicron abilities still cost 20

The change only affects GAC omis that specifically call out either 5v5 or 3v3, so omis like the ones for Doctor Aphra, BT-1, 0-0-0, Tusken Raider, etc. - those call out and are active only in one of the two versions. Meanwhile, omis like the ones for Ventress, Reva, Ben Solo, Exile Ezra, Dark Rey, Starkiller, those can be used in either version of GAC, so they remain the same. Captain Rex is also unaffected - he has clauses for 5v5 and 3v3, but they're part of an omi that is for GAC as a whole.