Improve error messaging for creating a Deployment that will violate quotas with high max-in-flight

Update from code review comments and cleanup

Author: nookala

app/actions/deployment_create.rb

@@ -87,18 +87,21 @@ def create(app:, user_audit_info:, message:)
       end
 
       def handle_deployment_create_error(e, app)
-        space_quota_errors = [:space_quota_exceeded.to_s, :space_app_instance_limit_exceeded.to_s]
-        org_quota_errors = [:quota_exceeded.to_s, :app_instance_limit_exceeded.to_s]
+        space_quota_errors = %w(space_quota_exceeded space_app_instance_limit_exceeded)
+        org_quota_errors = %w(quota_exceeded app_instance_limit_exceeded)
+        space_error_msg = " for space #{app.space.name}. This space's quota may not be large enough to support rolling deployments or your configured max-in-flight."
+        org_error_msg_1 = " for organization #{app.organization.name}. "
+        org_error_msg_2 = "This organization's quota may not be large enough to support rolling deployments or your configured max-in-flight."
+        org_error_msg = org_error_msg_1 + org_error_msg_2
+        error_message = e.message
+
         if space_quota_errors.any? { |substring| e.message.include?(substring) }
-          space_error_msg = " for space #{app.space.name}. This space's quota may not be large enough to support rolling deployments or your configured max-in-flight."
-          error = DeploymentCreate::Error.new(e.message + space_error_msg)
+          error_message += space_error_msg
         elsif org_quota_errors.any? { |substring| e.message.include?(substring) }
-          org_error_msg_1 = " for organization #{app.organization.name}. "
-          org_error_msg_2 = "This organization's quota may not be large enough to support rolling deployments or your configured max-in-flight."
-          error = DeploymentCreate::Error.new(e.message + org_error_msg_1 + org_error_msg_2)
-        else
-          error = DeploymentCreate::Error.new(e.message)
+          error_message += org_error_msg
         end
+
+        error = DeploymentCreate::Error.new(error_message)    
         error.set_backtrace(e.backtrace)
         error
       end