Adding a new item within a new template doesn't work

Since the retention feature, we observed an expected behaviour in the way that Nuxeo manages the template item when a new one is added.

The Retention addon, defines a new template item to add a new document model named RetentionRules
see here this document is used to manage the retention rules.
The problem that we have is we are not able to retrieve this document (404 error). After investigation it seems that no matter which Data Base we have, if we follow certain steps, we will be able to reproduce the problem easily:

Reproduction steps

1. Install Nuxeo Server
2. Add WebUI
3. Run nuxeoctl mp-hotfix
4. Run nuxeoctl start
5. Go go Nuxeo Server webUI
6. Ensure that there is no error in the server logs
7. Now stop you server
8. Run nuxeoctl mp-install nuxeo-retention-1.0.0-SNAPSHOT: this addon will add a new template with a new item entry (see above)

Observed behavior

3. Nuxeo Server with all HF including HF25 are installed

7. A 404 error is displayed and I can't create a retention rule

Expected behavior

3. Nuxeo Server with all HF including HF25 are installed

7. The retention rule creation popup is displayed and I can create a retention rule

From what we saw, the issue is not related to retention but it allows us to see the problem. The new template is handled correctly by the platform, but the new item (the document RetentionRules is not added), the reason here and the check
The code will exit if we find at least one item, this is the issue. Under H2 / Postgres starting the server before installing the retention addon, will end by creating the items entries that cames from other contributions (creation of Domain...). If we stop the server, install the retention addon and restart it. As the data is already exist in the D.B, the check will consider that the existence of Domain is enough and it will exist without adding the new one.