refactor(AnkiDroidApp): extract setup code

[david-allison]

Note

• split from improvement(startup): split into methods and add timing #20593

Purpose / Description

Before we handle setup failures, we should break AnkiDroidApp into initializing features, so we can determine whether a feature failing should be fatal

Fixes

• Part of Improve startup process & notifying users of nonfatal component errors #20168

Approach

Simple method extraction + use of setup

How Has This Been Tested?

See the linked PR

executed setupContextMenus in 470.125us
executed makeBackendUsable in 143.208us
Creating notification channel with id/name: General Notifications/AnkiDroid
Creating notification channel with id/name: Synchronization/Synchronization
Creating notification channel with id/name: Review Reminders/Review Reminders
AnkiDroidApp: Starting Services
executed setupNotifications in 3.405208ms
executed initializeAnkiDroidDirectory in 1.079ms
listening for rollover events
executed setupLifecycleLogging in 108.291us

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[criticalAY]

👌🏼, (CI should be green)