Implement backup and restore without storage permission

[unbiaseduser]

Hello. So, I have seen that this app advertises backup/restore feature but that functionality is missing in the actual app. Thus, I decided to look around in the code and I found out that the backup/restore code was actually present, but it seems to be tied to the storage permission. I have ported the code to use the ActivityResultContracts API, which requires no permission. I hope you can take a look at it.

[CrazyMarvin]

That's awesome, @unbiaseduser! Thank you very much.
Please check if we can merge it, @arafaatqureshi.

[arafaatqureshi]

@unbiaseduser Thank you so much for your input, i was still working with the same issue. Highly appreciated.
Let me go through your code, will merge it after that :)

[unbiaseduser]

@arafaatqureshi Any progress so far? This is taking a bit too long for a simple change.
Keep in mind that it is you who wrote the main backup/restore code and I just adapted it a little bit.
I really don't think that it should take days for you to review...

[unbiaseduser]

Oh thank you, good sir. I was worrying you would be inactive.