Use longer retry intervals when extension metadata requests fail

When CWSInfoService receives an errored response from the CWS server,
it retries the request every hour. This can result in a large number
of requests in some situations. This CL modifies the retry logic by
recording a fetch error timestamp. CWSInfoService will now wait for a
full fetch interval to elapse (since the last fetch error) before
attempting another fetch. The fetch interval already has some jitter
included so that the requests are staggered across clients.

Bug: 41497356
Change-Id: I06224ae0d467ac4df6293a475222a01137339125
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5269961
Reviewed-by: David Bertoni <dbertoni@chromium.org>
Commit-Queue: Anunoy Ghosh <anunoy@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1256487}