[autotest] Sync completed jobs back to master

Records of jobs that are completed should be send back to the master
upon a heartbeat.

This changes the heartbeat to include these things.

BUG=None
CQ-DEPEND=CL:212725
DEPLOY=apache,afe
TEST=Ran suites, tried out manually

Change-Id: I25daed310dc1bad064bd0c4819a43d18ba04606d
Reviewed-on: https://chromium-review.googlesource.com/218730
Tested-by: Jakob Jülich <jakobjuelich@chromium.org>
Reviewed-by: Fang Deng <fdeng@chromium.org>
Commit-Queue: Jakob Jülich <jakobjuelich@chromium.org>
diff --git a/global_config.ini b/global_config.ini
index 793a8e9..1468d88 100644
--- a/global_config.ini
+++ b/global_config.ini
@@ -32,12 +32,11 @@
 sql_debug_mode: False
 
 [SHARD]
-# Whether this AFE is running as master AFE or as slave shard.
-is_slave_shard: False
-# Hostname of the local shard, only used if is_slave_shard
-shard_hostname: SET IN SHADOW CONFIG
-# Ignored if is_slave_shard is False
-global_afe_hostname: SET IN SHADOW IF is_slave_shard=True
+# If this is not None, the instance is considered a shard.
+# The value should be the hostname of the local shard.
+shard_hostname:
+# Ignored if shard_hostname is None
+global_afe_hostname: SET IN SHADOW IF shard_hostname IS NOT NONE
 heartbeat_pause_sec: 60
 
 [AUTOSERV]