Clean up the use of profile_key / dex_locations

The profile key / dex locations names were sometimes used interchangeably
despite not being quite the same. Make clear, through renaming, which one
is which.

Bug: 139884006
Test: m test-art-host
Change-Id: I9c79b2f2e577b873ee890333895cc90a7891499e
3 files changed