Migrates legacy dropdown in metric-chart

What does this MR do and why?

This MR migrates legacy GlDropdown to GlListbox according to OKR

Resolves #418046 (closed)

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

UI	Description
dropdown_before.mov	Before
dropdown_after.mov	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Go to a group
2. Analyze -> Productivity Analytics -> Trendline charts top left corner

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.