Fix unstable FixedThreadPoolConfigBeanTest

Test was failing because threads were not cleaned
up right after the thread pool was shut down. Test now
waits up to 60 seconds before failing on threads
that should have been destroyed.

Change-Id: Ie9ac856007772f39426dbcbb2af0fb66226fc2c0
Signed-off-by: Tomas Olvecky <tolvecky@cisco.com>
Merge "Fix unstable FixedThreadPoolConfigBeanTest"