Unit tests are taking longer than usual since [1] and
causing timeouts in unit tests jobs intermittently. Set
report_interval(as this is now used to set RPC timeout)
to 0 so report_state responds immediately.
[1] https://review.opendev.org/q/I8a95e80ca74edc8f8f394cefc749c4065a8e0575
Related-Bug: #1948676
Change-Id: I653c907a4323e19d5bc381cd3716d42c45a75e15
(cherry picked from commit a4ffd1a2f9)