Increase Ubuntu volume to 50GB.

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: Id867b748bc7dfd2a5052a63dcd6ffa5cfd81b202
diff --git a/packer_ubuntu.json b/packer_ubuntu.json
index 139d6a8..535935c 100644
--- a/packer_ubuntu.json
+++ b/packer_ubuntu.json
@@ -33,7 +33,7 @@
         {
           "device_name": "/dev/sda1",
           "volume_type": "gp2",
-          "volume_size": "30",
+          "volume_size": "50",
           "delete_on_termination": true
         }
       ]