Wait for the network to start AOS on the pi's

Otherwise we get ourselves stuck in some weird state and don't recover.

Change-Id: I729b4b791f911a19e8dca77d6f6b526f8abb4c06
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2020/vision/rootfs/frc971.service b/y2020/vision/rootfs/frc971.service
index 0066517..cdfb347 100644
--- a/y2020/vision/rootfs/frc971.service
+++ b/y2020/vision/rootfs/frc971.service
@@ -1,5 +1,7 @@
 [Unit]
 Description=Start up 971 robot code
+Requires=network-online.target
+After=network-online.target
 
 [Service]
 User=pi