Wait after fetch exception on topic

Wait after fetch exception on topic

When dmaap is inaccessible for some reason, the topic source frequently
enters a fast fail loop, rapidly filling up the log.  Modified the code
to wait the configured fetchTimeout when this occurs.

With any luck, this will also fix the sporadic kubernetes crash-fail
loops sometimes seen with the xacml-pdp pod.

Modified to limit how long it will sleep after a failure, regardless of
the fetchTimeout that was specified.

Issue-ID: POLICY-3457
Change-Id: I88e360fb1d31197b46f4959e5ea0ea2d741ad25c
Signed-off-by: Jim Hahn <jrh3@att.com>