Output kernel version during VHD build (#4176)

packer/install-dependencies.sh

@@ -4,6 +4,10 @@ source /home/packer/provision_installs.sh
 source /home/packer/provision_source.sh
 source /home/packer/feature-flagged.sh
 
+echo "Starting build on " `date` > /var/log/azure/golden-image-install.complete
+echo "Using kernel:" >> /var/log/azure/golden-image-install.complete
+cat /proc/version | tee -a /var/log/azure/golden-image-install.complete
+
 ETCD_VERSION="3.2.24"
 ETCD_DOWNLOAD_URL="https://acs-mirror.azureedge.net/github-coreos"
 installEtcd
@@ -129,7 +133,7 @@ done
 
 df -h
 
-echo "Install completed successfully on " `date` > /var/log/azure/golden-image-install.complete
+echo "Install completed successfully on " `date` >> /var/log/azure/golden-image-install.complete
 echo "VSTS Build NUMBER: ${BUILD_NUMBER}" >> /var/log/azure/golden-image-install.complete
 echo "VSTS Build ID: ${BUILD_ID}" >> /var/log/azure/golden-image-install.complete
 echo "Commit: ${COMMIT}" >> /var/log/azure/golden-image-install.complete