[Metrics] Improve ManualAppStartup

[rlinoz]

Objective

We want to improve the App Start Time performance metric.

Target: 5 seconds

You can check the current values and monitor progress at:
https://expensify.sentry.io/dashboard/166320/?statsPeriod=14d

[rlinoz]

Related #74832

[rinej]

Hello, I'd like to work on that issue

[melvin-bot]

@rinej, @rlinoz Uh oh! This issue is overdue by 2 days. Don't forget to update your issues!

[melvin-bot]

@rinej, @rlinoz 6 days overdue. This is scarier than being forced to listen to Vogon poetry!

[rlinoz]

Hey @rinej any progress on this one?

[melvin-bot]

@rinej, @rlinoz Uh oh! This issue is overdue by 2 days. Don't forget to update your issues!

[rinej]

Hey! I was focusing on some other auth errors and other metrics, but I’m coming back to this now.
I’ve started the investigation already. We looked into reducing the bundle size, but it didn’t give the expected results. I do have some potential ideas that could improve it and I’ll continue working on it