EGL BlobCache: Don't check system property during init

Trying to isolate why there is a slowdown when multifile is already
disabled via config.

This is a cherry-pick from master.

Test: Boot
Bug: b/266725576
Bug: b/268595699
Change-Id: I6dafcc1c5068042f7fb977b0ee012910db7f7419
Merged-In: 91307c64