Fix BK DRA pipeline

[dliappis]

Proposed commit message

This commit fixes the error
"interpolating remaining fields: Expected identifier to start with a letter, got /"

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @dliappis? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v8./d.0 is the label to automatically backport to the 8./d branch. /d is the digit

[elasticmachine]

💔 Build Failed

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Build stats

• Duration: 5 min 41 sec

Pipeline error

This error is likely related to the pipeline itself. Click here
and then you will see the error (either incorrect syntax or an invalid configuration).

❕ Flaky test report

No test was executed to be analysed.

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