App takes way too long on start with huge music library

[resynth1943]

Shuttle version:

v2.0.15

Device, OS:

Android 10; GrapheneOS.

Pixel 2 XL.

Description of bug:

I currently have a music library upwards of 20GB on my phone. When Shuttle is started, this causes a shocking amount of lag before any music is shown in the library

Steps to reproduce:

1. Step 1 be crazy and build up a 20GB music library on your phone
2. Step 2 Start Shuttle
3. Step 3 Prepare for eternal doom!

Expected outcome:

The application doesn't lag. Phonograph handles this perfectly, which actually took me by surprise.

[resynth1943]

Related to #79, but I don't use an SD Card. Instead, all media is stored in Internal Storage. I'd be happy to run a logcat, but no guarantees on that as I've never had to do it before.

[resynth1943]

Possibly related to #357?