[autotest] Add a reserve role for server db

BUG=chromium:495762
TEST=local

Change-Id: Icfd39fdecb86f89c0a25f13865676f592ae350a7
Reviewed-on: https://chromium-review.googlesource.com/274815
Commit-Queue: Dan Shi <dshi@chromium.org>
Trybot-Ready: Dan Shi <dshi@chromium.org>
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
1 file changed