Merge pull request #14981 from lfu/dialog_field_sort_none_1389010

Add :sort_by: :none to GCE Boot Disk Size dialog field.
(cherry picked from commit f86c62d)

https://bugzilla.redhat.com/show_bug.cgi?id=1458447

product/dialogs/miq_dialogs/miq_provision_google_dialogs_template.yaml

@@ -282,6 +282,7 @@
           :required: true
           :display: :edit
           :data_type: string
+          :sort_by: :none
         :instance_type:
           :values_from:
             :method: :allowed_instance_types