http://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20arm%20-%20sim%20-%20debug
V8 Linux ARM SIM Debug bot runs into timeouts consistently in "Check - extra"
suite shard#1 after 45 minutes (shard#1 and shard#2 run for 40~ minutes) due to
unbalanced sharding.

This CL increases the shard size for the bot

R=yangguo@chromium.org
CC=​machenbach@chromium.org,sergiyb@chromium.org

Bug: v8:8174
No-Try: true
Change-Id: I47fdc2568ff93fb88eda5121d45b6f9d86e596a5
Reviewed-on: https://chromium-review.googlesource.com/c/1456096
Commit-Queue: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59392}