Update tests with 'while True' loop

Some tests use a 'while True' loop to send queries to the DNS server
However, none of them pause between queries, which can lead to high
load on the DNS server.
This patch adds a delay between each query iteration.

Related-Prod: PRODX-57822
Change-Id: I24dcb791f1dde1f26693a118a9ad76776609eca7
(cherry picked from commit 815d3a4113b005951c4b5d2a275c08fbb566f1f8)
3 files changed