Adjust ResolveRelativeEncodedDexLocation.

Now that jar files are in the apex, relax the prefix check between
the absolute location of the oat file and the jar location for host
compilation.

For example we now have:
- /system/framework/boot-core-oj.art
- /apex/com.android.runtime/core-oj.jar

Whereas before, the jar and the art file had the same prefix path.

Test: m

Change-Id: Ic216229dab7a853c64c98a36e32b387559f9cc0d