Deprecate ServiceWorker.Storage.RetryCountForRecovery

As far as I checked the recent UMA, the count is almost 0.
I can see several times out of more than 10 million times on Windows.

I believe we can delete the metrics.

OBSOLETE_HISTOGRAM[ServiceWorker.Storage.RetryCountForRecovery]=The metric is no longer useful.

Fixed: 377305338, 40150911
Change-Id: I95227e90d80a9e1744a79f745f329dd64a340a05
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6002453
Commit-Queue: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Reviewed-by: Shunya Shishido <sisidovski@chromium.org>
Reviewed-by: Keita Suzuki <suzukikeita@chromium.org>
Reviewed-by: Minoru Chikamune <chikamune@chromium.org>
Auto-Submit: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1379510}