[autotest] Add new roles to server database: shard, golo_proxy

BUG=chromium:444625
TEST=None

Change-Id: Ifb696d4dfd723258c5c1de0601967b3a349d3c7a
Reviewed-on: https://chromium-review.googlesource.com/238391
Commit-Queue: Dan Shi <dshi@chromium.org>
Trybot-Ready: Dan Shi <dshi@chromium.org>
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Fang Deng <fdeng@chromium.org>
diff --git a/frontend/server/models.py b/frontend/server/models.py
index 876a78e..43379c7 100644
--- a/frontend/server/models.py
+++ b/frontend/server/models.py
@@ -71,7 +71,8 @@
     """Role associated with hosts."""
     # Valid roles for a server.
     ROLE_LIST = ['scheduler', 'host_scheduler', 'drone', 'devserver',
-                  'database', 'suite_scheduler', 'crash_server']
+                  'database', 'suite_scheduler', 'crash_server', 'shard',
+                  'golo_proxy']
     ROLE = enum.Enum(*ROLE_LIST, string_values=True)
     # When deleting any of following roles from a primary server, a working
     # backup must be available if user_server_db is enabled in global config.