Modify startup_timeline_framework_start probe to get it to start working

[mcomella]

In mozilla/glam#1141, we determined that having client_id disabled in the ping configuration breaks these probes. That issue will take some time to fix so to get the data in the short term, we can:

• add client_ids back into the ping
• move the metrics into the events and metrics pings

The second one seems nice because having to manually transmit our ping adds complexity to the implementation and thus risks adding errors to the results. However, it's more code to change for perhaps no gain if it's implemented correctly. Let's do it if it's simple.

┆Issue is synchronized with this Jira Task

[mcomella]

move the metrics into the events and metrics pings

This isn't possible because the TimingDistribution type doesn't support raw nanos and, without a custom ping, we can't guarantee the timespan type will have been cleared before it's sent.

[mcomella]

Merged in 359f27a

[mcomella]

move the metrics into the events and metrics pings

This isn't possible because the TimingDistribution type doesn't support raw nanos and, without a custom ping, we can't guarantee the timespan type will have been cleared before it's sent.

I missed this API but it's too late: https://mozilla.github.io/glean/javadoc/glean/mozilla.telemetry.glean.private/-timing-distribution-metric-type/accumulate-samples.html