Prepare moving bots for win-10_amd_laptop-perf

The bots for win-10_amd_laptop-perf will be moved from MTV to SFO.
win-2-b220 has already been moved and renamed to win-141-e504.
The rest of the bots will be moved in the next few days.

Making two config changes in preparation for the move:
* Slightly relax OS version filter. The OS is expected to change from
  Windows-10-19043.1052 to Windows-10-19043.2364 after the move.
* Reduce shard count from 5 to 3. The plan is to move 5 bots at a time,
  so that only 5 bots are available sometimes. As it turns out, we were
  only using 3 shards any way, even though 5 shards were allocated.

Change-Id: Ib59618bcd0f2bf11e40f2a32a2acfff01b29668d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5121074
Commit-Queue: John Chen <johnchen@chromium.org>
Reviewed-by: Wenbin Zhang <wenbinzhang@google.com>
Cr-Commit-Position: refs/heads/main@{#1237313}