Improvements to JarFileTest

The main purpose of this change is to perform a cert chain
loop test on the main thread. The test is deterministic and
should not need additional threads. The test flaked on a
gc-stress environment.

The other changes are improvements to the code:
1) Close JarFiles that would otherwise be left open and left
to the finalizer to close.
2) Remove unnecessary File object creation that duplicates
a readily available File object return value and adds noise to
test code.

Test: Ran test under vogar
Change-Id: If67ebe4b6e3a384b39ceaf480ecd62939c6a732c

0 files changed, 0 insertions, 0 deletions