Is your feature request related to a problem? Please describe.
Support Core Web Vitals #2092

Describe the solution you'd like
Need additional standard metrics for tracking browser paint metrics

Existing Standard metric browserTimings/totalDuration
Existing Standard metric browserTiming/processingDuration
Existing Standard metric browserTimings/sendDuration
Existing Standard metric browserTimings/receiveDuration

New proposal browserTimings/firstPaint - First Paint
New proposal browserTimings/firstContentfulPaint - https://web.dev/fcp/
New proposal browserTimings/primeryPaint - Time at which primary content of the page is painted on the screen
New proposal browserTimings/secondaryPaint - Time at which secondary content is painted on the screen

Describe alternatives you've considered

• Using custom metrics
• Adding additional properties in page view event