JetPlayerTest: cleanup JetPlayer test

Eliminate failures caused by not closing the file on the previous test.
Fail immediately when a file cannot be loaded.

There have been intermittent failures in this test.
These changes may help us track down the cause.

Bug: 23161123
Change-Id: If1ba46c6bf02f190fcaf4315a72e54172ea5ce02
Signed-off-by: Phil Burk <philburk@google.com>
1 file changed