If auto lock is set to instant files cannot be uploaded

### Description

If auto lock (`Lock after`) is set to `Instant`, cannot be uploaded because vault is locked instantly after switching to the files app.

### System Setup

* Android version: x
* Cryptomator version: 1.5.x
* Cloud type: x

### Steps to Reproduce

1. Go to settings
2. Select `Instant` in the `Lock after` setting
3. Upload file to vault

#### Expected Behavior

See `Description`

#### Actual Behavior

See `Description`

#### Reproducibility

Always

#### Workaround

Set `Lock after` to something like `1 minute`