[teamd service] start teamd service after swss (sonic-net#2829)

SWSS clears DB tables, if teamd is not started after swss, there is a
race condition that swss might clear vital teamd information.

Signed-off-by: Ying Xie <[email protected]>

Author: yxieca

files/build_templates/teamd.service.j2

@@ -1,7 +1,7 @@
 [Unit]
 Description=TEAMD container
 Requires=updategraph.service
-After=updategraph.service
+After=updategraph.service swss.service
 Before=ntp-config.service
 
 [Service]