Decide if telemetry expiring in April should be removed or extended.

[mcarare]

Breakout from #17768.

The metrics expiring in April are:

• Telemetry App Entry Point #968 - Telemetry App Entry Point
• Telemetry Address Bar + Search #959 - Telemetry Address Bar + Search (search bar tapped, entered_url, performed_search)
• Telemetry 3dot menu #1024 - Telemetry 3dot menu (browser_menu_action = browser menu item was tapped)
• [Telemetry] What's New #5021 - What's New Telemetry
• [Telemetry] "Launch links in private tab" toggle #5737 - Telemetry for "Launch links in private tab"
• [Telemetry] New tab shortcuts #11442 - Tab tray tab counter menu item was tapped
• Telemetry to Crash Reporting Page #1040 - Crash Reporting Telemetry
• Telemetry for share intents #957 - Telemetry for browser context menu
• Telemetry for Bookmarks #974 - Telemetry for Bookmarks
• Telemetry for Custom tabs #977 - Telemetry for Custom tabs
• https://bugzilla.mozilla.org/show_bug.cgi?id=1538011 - Glean
• [Telemetry] Error Pages #1242 - Telemetry for Error Pages
• Telemetry for Collections #969 - Telemetry for Collections
• [Telemetry] CFR message about Enhanced Tracking Protection panel #9625 - Telemetry for ETP CFR
• [Telemetry] Download notifications #5583 - Telemetry for Download notifications
• [Telemetry] Download events #11578 - Downloads counter
• [Telemetry] View Downloads #15367 - Telemetry for Downloads Management
• [Telemetry] About Firefox Preview #6834 - Telemetry for About page
• [Telemetry] Dark Theme #7289 - Telemetry for Dark Theme selection
• [Telemetry] WebExtensions #6174 - WebExtensions Telemetry + [Telemetry] Send add-on ids in separate ping #8920

cc @vesta0 for deciding if all should be extended.

┆Issue is synchronized with this Jira Task

[vesta0]

Let's keep all for now and re-evaluate in June.

[clientenq]

Since telemetry data does expire for several reasons it does not sound sufficient to just extend retention to decide later.
Telemetry data is collected and maintained under conditions and should thus per data have valid substantial reasons to be able to keep the data.
How is the current reply sufficient to extend to June?

[clientenq]

I sure would expect a human answer to this pricacy question. Just dismissing it does not solve any problem.