Cannot select multiple files when importing files

### Description

When I import external audio files to Pocket Casts I expect to be able to multi-select them in order to import in bulk. The UI seems like it should support this after I long hold a file, but then only allows me to select one file for import at a time.

I have a series of talks in about 100 different audio files which I have to import one at a time instead of being able to bulk select and import them at once, which is enough of a UX burden that I won't bother using Pocket Casts to listen to this particular series.

### Step-by-step reproduction instructions

1. Open Pocket Casts on Android.
2. Click "Profile" on the bottom right.
3. Click "Files" in the menu which appears.
4. Click the "+" button on the bottom right to add files.
5. With multiple audio files available on your device, select the "audio" type on the top bar.
6. Long hold on a file.
7. Observe that "1 selected" appears on the top of the screen, seeming to indicate that you could have "2 selected".
8. Click another file to select more files for import.
9. Observe that this undoes your prior selection, selects the next file, and you still see "1 selected" on the top of the screen.

### Screenshots or screen recording

_No response_

### Did you search for existing bug reports?

- [X] I have searched for existing bug reports.

### Device, Operating system, and Pocket Casts app version

Google Pixel 6, Android 13.0.0, Pocket Casts 7.25

Start at the Android import flow reached through Profile > Files > the + button, and reproduce the selection behavior with multiple audio files. Trace the screen that handles long-press selection; done means multiple files remain selected and can be imported together.

Written by the indexing model from the issue text.