Summary:
This test is flaky in alma8-clang19-release, alma8-clang19-release-aarch64
and alma8-gcc11-fastdebug.

The flakiness is because at the end of the test, we check the ASH circular
buffer for nested queries, which shouldn't be present. I have verified that
YSQL is not sending this query id to tserver. But sometimes the same query
id is observed in tserver, likely because we are scheduling an rpc in
YBTransaction::Impl::HeartbeatDone which is not completed in time in the
tests.

Increasing the sleep time also fixes the issue, so this is likely not a bug in
ASH. This diff updates the test query string to only include ysql samples.

Jira: DB-16487

Test Plan:
./yb_build.sh release --java-test TestYbAsh#testNestedQueriesWithAsh --clang19 -n 100
./yb_build.sh fastdebug --java-test TestYbAsh#testNestedQueriesWithAsh --gcc11 -n 100

Reviewers: hbhanawat, ishan.chhangani

Reviewed By: ishan.chhangani

Differential Revision: https://phorge.dev.yugabyte.com/D44766