[res] Optimize Idmap actor matching

Only perform the actor matching for overlayable.xml definitions
if current device defines some actors. Most of the devices do
not, making all the overlayable loading, parsing and getting
work to go to waste

Bug: 282215580
Test: build + boot + presubmits
Change-Id: I4256ef7d6a8dc0e27485415a5ef721a341156849