Fix fstab mounting

Properly escape fstab entry to mount EFS for gerrit master.
The user-data script was incorrectly escaping the enclosing quotas,
causing the final entry to be quoted and the internal tab characters to
be replaced with the literal 't'.

Bug: Issue 13729
Change-Id: Iabfbbc6311f7540ed840597a440ef8c90d364c95
diff --git a/common-templates/cf-master-asg.yml b/common-templates/cf-master-asg.yml
index 3d26c45..0840168 100644
--- a/common-templates/cf-master-asg.yml
+++ b/common-templates/cf-master-asg.yml
@@ -105,7 +105,7 @@
           mkdir -p $DIR_TGT/high-availability
           chown -R 1000:1000 $DIR_TGT
           cp -p /etc/fstab /etc/fstab.back-$(date +%F)
-          echo -e \"$DIR_SRC:/ \t\t $DIR_TGT \t\t nfs \t\t defaults \t\t 0 \t\t 0\" | tee -a /etc/fstab
+          echo -e "$DIR_SRC:/ \t\t $DIR_TGT \t\t nfs \t\t defaults \t\t 0 \t\t 0" | tee -a /etc/fstab
           # Get the CloudWatch Logs agent
           echo -e "
             {\"logs\":