The results of CollectLocations() are only used if the --proguard-conditional-keep-rules option is set, but the function is always called when the --proguard option is set.
Since this function can be slow on particularly large resource sets, avoid calling it unless --proguard-conditional-keep-rules is set.
Change-Id: If259d41cdab16abad8ca62f30d8beb5ebf33575a
Bug: 144236322
Test: aapt2_tests
2f7e4d1a82