[k6] Lower load for legacy async batch operation test

Legacy async batch operation test is failing and reporting zero
as result due to timeouts in the test.

- Lower total batch requests to 100 instead of 1000
- Limit the number of kafka messages per batch to 200 instead of 1000
  to avoid timeout issues.

Issue-ID: CPS-2274
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: I06c04173ca1ed0f3580df6a73b5d647ab7ed0c71
2 files changed