Update Auto DevOps docker version to 19.03.8

What does this MR do?

Updates the docker used by Auto DevOps to 19.03.8. The issue affecting the runners in 19.03.6 should be fixed since 19.03.7 (see gitlab-runner#6697 (closed)).

Updating auto-build-image alongside to keep both sides of the docker images in sync (v0.2.1 is based on 19.03.8 and includes one additional small fix)

See also Docker release notes.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team