Further improve debug logging for 77342775

Previous logging had long log lines that were truncated.

For multidex, replace the base location for other than the
first dex file with "+". Split the first line into two, so
that if there are too many dex files in the class loader,
we still get to see at least some of them also for the other
class loader.

Test: Manual; change 108-check-cast to multi-dex and disable
      the Lorg/apache/http/ filtering, check error message.
Bug: 77342775

Change-Id: I702db6912f9f3b1b95ad9333913b19bbcc50fc3b