feat: Add time to first draw span for app screen

[limhjgrace]

Fixes #2830

Changes

This PR proposes the a span definition for an application screen's time to first draw following spans (spanName = span.app.screen.time_to_first_draw.internal)

Revisions

• Rev2: Rev1-Rev2 diff 1. App start span with only cold and warm values defined 2. Time to first appear client span --> time to first draw internal span 4. Screen load client span --> screen load internal span. Definition also changed: Time to main thread idle --> time to first stable frame 5. Screen visible client span --> screen visible event
• Rev3: Rev2-Rev3 diff 1. App start client span --> app start internal span. Clarified end time to be the moment before UI rendering begins. 2. Removed screen load span. Will raise separate PR to get other proposals unblocked. 3. Unit fix (ns -> s) 4. Type fix (int -> double) 6. Rename app.screen.first_draw --> app.screen.time_to_first_draw 7. app.visible event -> app.time_on_screen internal span
• Rev4: Rev3-Rev4 diff 1. Removed *.duration attributes 2. Removed app start span so that it is reviewed in a separate PR: https://github.com/open-telemetry/semantic-conventions/pull/2965 3. Removed span.app.time_on_screen.internal

Merge requirement checklist

• [X] CONTRIBUTING.md guidelines followed.
• [X] Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• [ ] Links to the prototypes or existing instrumentations (when adding or changing conventions)

[github-actions[bot]]

This PR contains changes to area(s) that do not have an active SIG/project and will be auto-closed:

• app

Such changes may be rejected or put on hold until a new SIG/project is established.

Please refer to the Semantic Convention Areas document to see the current active SIGs and also to learn how to kick start a new one.

[limhjgrace]

It looks like the PR was auto closed because there's no dedicated SIG for area:app. @thompson-tomo could I know how to proceed forward in getting this PR reviewed? Similar scenario for the PR I created for app start: https://github.com/open-telemetry/semantic-conventions/pull/2965

[lmolkova]

@limhjgrace I believe this should fix the automation: https://github.com/open-telemetry/semantic-conventions/pull/2968 (but until it's merged any push would close this PR again, sorry about this)

[github-actions[bot]]

This PR was marked stale due to lack of activity. It will be closed in 7 days.