profiler: increase the test bench duration
profiler: increase the test bench duration

In very unlucky case, the deployment can be moved to another backend task
so that not all types get profiled in 150s, see
https://github.com/googleapis/google-cloud-go/issues/1568.

Change-Id: Iba7c32d4700cb7ed823a85ef16b4852294aa1187
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/46070
Reviewed-by: Kalyana Chadalavada <c332291e072201764060f4798582a335683bdc9c@google.com>

googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go