App crashes if permissions not given

[mdhishaamakhtar]

Describe the bug
The app asks for permission at the starting in the splash screen but if permissions are granted and manually removed, it isn't asked again and the app crashes when camera is accessed

To Reproduce
Steps to reproduce the behavior:

1. Open the app and accept the permissions
2. Remove the permissions manually from the device
3. Login using any credentials and try to join a club. Press the QR code button to scan a QR code and the app crashes

Expected behavior
If permissions are taken away manually, the app should ask for permission again

Environment
Android 11 phone with MIUI

Possible solution
Add a check when camera opens for permission

Additional context
Discovered by @BRO3886