Fix DistributedTransactionAdminIntegrationTestBase

[brfrn169]

Description

This is for the 3 and 3.13 branches.

Depending on the environment executing the integration tests, DistributedStorageAdmin can't be instantiated. This PR moves the instantiation to extraCheckOnCoordinatorTable().

Related issues and/or PRs

• Use a proper coordinator table schema based on whether the group commit feature is enabled or not #2034

Changes made

• Fixed DistributedTransactionAdminIntegrationTestBase.

Checklist

• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes.
• Any remaining open issues linked to this PR are documented and up-to-date (Jira, GitHub, etc.).
• Tests (unit, integration, etc.) have been added for the changes.
• My changes generate no new warnings.
• Any dependent changes in other PRs have been merged and published.

Additional notes (optional)

N/A

Release notes

N/A

[brfrn169]

Since this is a very minor change, I will merge it without reviews.