[Arista]: Fix the udev waiting in networking start (#1093)

* [Arista]: Fix the udev waiting in networking start

This change is to fix the issue in aristanetworks/sonic#16
For the checking condition used, it is only applied to Arista switches

Signed-off-by: Boyang Yu <byu@arista.com>

* [Arista]: Correct for PR comments

Signed-off-by: Boyang Yu <byu@arista.com>

files/build_templates/sonic_debian_extension.j2

@@ -188,6 +188,11 @@ sudo dpkg --root=$FILESYSTEM_ROOT -P {{ debname }}
 
 sudo rm -f $FILESYSTEM_ROOT/usr/sbin/policy-rc.d
 
+## Revise /etc/init.d/networking for Arista switches
+if [ "$image_type" = "aboot" ]; then
+    sudo sed -i 's/udevadm settle/udevadm settle -E \/sys\/class\/net\/eth0/' $FILESYSTEM_ROOT/etc/init.d/networking
+fi
+
 ## copy platform rc.local
 sudo cp $IMAGE_CONFIGS/platform/rc.local $FILESYSTEM_ROOT/etc/