[7.12] [Maps] fix selecting EMS basemap does not populate input (#92711)

[nreese]

Backports the following commits to 7.12:

• [Maps] fix selecting EMS basemap does not populate input ([Maps] fix selecting EMS basemap does not populate input #92711)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 252c528
• Storybooks Preview

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
maps	692	693	+1

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
maps	2.6MB	2.6MB	+883.0B

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream