Reviewer: migrate requested files immediately

[david-allison]

Purpose / Description

During a storage migration, we have some media in an old folder and others in the collection media folder.

Instead of handling the possibility of 2 folders, we immediately migrate requested files when requested by the reviewer/previewers

Fixes

• Related: Enhancement: AnkiDroid should not use Storage permission (Deadline November 2021) #5304

Approach

When an image/sound file is requested, and is:

• not found
• inside the collection
• available for migration

Add a new task to prioritise it in the storage migration

Image migration: needs to be performed in shouldInterceptRequest as WebClient error handlers do not provide enough control to recover from

Sound: performed in the error handler to avoid impacting the fast path

How Has This Been Tested?

API 31/33 emulator.

The migration performance hit is not noticeable in my testing

Learning (optional, can help others)

Using CountDownLatch - constructor is very light

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

[mikehardy]

LGTM