Increase shards for android buildbot

I increased shards for some tests took time on
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/android-marshmallow-arm64-rel/59189

Bug: 868114
Change-Id: I9ae5c80e0fe641f8946e0d00d8a322721d2de079
Reviewed-on: https://chromium-review.googlesource.com/1170922
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582381}
5 files changed