ART: Restrict dex cache location check

Restrict the location check to the boot classpath. For app images,
the dex caches will contain the relative location, only.

For now, this is acceptable, as the location is only a debug feature.
Eventually, we may consider resetting the string.

Bug: 130666977
Test: m test-art-host
Change-Id: I14e3968dffef31a7c95d3e06c55c85744487844c
1 file changed