[autotest] Reroute some RPCs called to a shard to master

create_job and create_suite_job RPCs should not be handled by a shard.
They should be redirected to the master.

BUG=chromium:503188
TEST=puppylab. Submit a dummy suite in a stumpy shard.

Change-Id: Ibe432655c677024e9eee1f4aca118ef6db7951f7
Reviewed-on: https://chromium-review.googlesource.com/281818
Reviewed-by: Mungyung Ryu <mkryu@google.com>
Commit-Queue: Mungyung Ryu <mkryu@google.com>
Tested-by: Mungyung Ryu <mkryu@google.com>
diff --git a/frontend/afe/rpc_interface.py b/frontend/afe/rpc_interface.py
index 37050bf..20c5383 100644
--- a/frontend/afe/rpc_interface.py
+++ b/frontend/afe/rpc_interface.py
@@ -827,6 +827,7 @@
                       hostless=hostless, **kwargs)
 
 
+@rpc_utils.route_rpc_to_master
 def create_job(name, priority, control_file, control_type,
                hosts=(), meta_hosts=(), one_time_hosts=(),
                atomic_group_name=None, synch_count=None, is_template=False,