Change B&A requests to use recencyMs instead of recency
All released version of B&A support both the new and old fields. The
new field allows the B&A server to provide the same precision to
worklets as is available in on-device auctions.
Bug: 374088337
Change-Id: Ia1a5d40501da41300c7d9fd5e4e3bd7bfc8303ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5940498
Reviewed-by: Maks Orlovich morlovich@chromium.org
Commit-Queue: Russ Hamilton behamilton@google.com
Cr-Commit-Position: refs/heads/main@{#1370523}