[Starfish] Measure content provider and application class creation using AppComponentFactory

[markushi]

Description

Similar to papa we want to not only measure the .onCreate() timings, but rather the whole initialization, including class loading and any static init timings.

This is only available on Android P and above. More docs about AppCompontentFactory can be found here. It's usually registered via AndroidManifest.xml:

<application
    android:appComponentFactory="com.example.MyAppComponentFactory" />

Things to consider:

• Could we auto install a SentryAppComponentFactory factory?
• How to deal with user-defined factories?
• How to deal with it pre P?