In several places, we're including rc_timestamp or other fields in a
query selecting on rc_this_oldid because there was historically no index
on the column.
The needed index was created by I0ccfd26d and deployed by T202167, so
let's remove the hacks.
Bug: T139012
Bug: T239772
Change-Id: Ic99760075bde6603c9f2ab3ee262f5a2878205c7