Make a copy of the sSlotIndexToSubId's entryset

If sSlotIndexToSubId is modified on another thread between simInfoSet
being initialized and the iteration, the sizes may not match and an
array-out-of-bounds error may occur.

Change-Id: If1ed9678d5652f1e3161a7a29d34c047daa8e469
Test: builds
Fixes: 63715198