feature #2259: Use EBS_SNAPSHOT attar

src/cloud/ec2/lib/ImageEC2.rb

@@ -100,9 +100,10 @@ class ImageEC2 < Image
 
     def ec2_ami?
         self["TEMPLATE/EC2_AMI"] == "YES"
+        true
     end
 
     def ebs_snapshot?
-        !ebs_volume? && !ec2_ami?
+        self["TEMPLATE/EBS_SNAPSHOT"] == "YES"
     end
 end

src/cloud/ec2/lib/ebs.rb

@@ -297,6 +297,7 @@ module EBS
         end
 
         snapshot.delete_element("TEMPLATE/EBS_VOLUME")
+        snapshot.add_element('TEMPLATE', {"EBS_SNAPSHOT" => "YES"})
         snapshot.update
 
         erb_version = params['Version']