Add missing run_tag directive.

[psigen]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

The docker run command fails because it is missing a run_tag arg due to a missing line merged in #1957.

Issue Number: N/A

What is the new behavior?

The docker run command succeeds and runs as per documentation.

Does this PR introduce a breaking change?

• Yes
• No

Other information

The line "%{run_tag}": run_tag, was omitted during this merge commit:
922e466#diff-2a6edca3d784a368586063a7774b7551bbf4476c7345c511ab987bf95c610527L281

Referenced in this comment on the original PR:
#1957 (comment)

[psigen]

This might need to be merged quickly to unbreak master, but I would really love to add a test for this in a followup PR. Is there a good place in testing/e2e?

[alexeagle]

+1 on adding some missing e2e for this, thank you.
I'm not sure where that goes.

Will merge this now to unbreak HEAD, thanks for explaining your analysis of what happened.

[psigen]

Just confirmed that behavior is as expected post-merge on master right now.

Tested bazel run on a go_image target with and without --norun flag and passed some volume and env flags to the docker daemon with expected results.