KUDU-2882: Increase the timeout value for TestSentryClientMetrics.Basic
KUDU-2882: Increase the timeout value for TestSentryClientMetrics.Basic

It will be better to increase the timeout value to avoid the failures
in some test environments.

Change-Id: I3f7f1dc0887b31c4e1a56071be2f0223aeb292e9
Reviewed-on: http://gerrit.cloudera.org:8080/13770
Tested-by: Kudu Jenkins
Reviewed-by: Andrew Wong <b68e4fdc6430321a6b47400732ff97d7ae91234e@cloudera.com>

helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu