Get Tor running

[HenrikJannsen]

According to @alvasw Tor should already be supported on Android.
I fixed some code related issues but could not get the tor binary started as it was not the correct architecture (arm).

We resolve, download, verify, extract and zip the Tor binary via a Gradle task in Bisq 2. We should re-use that for Bisq-mobile (best without duplicating it). Though for initial dev testing we could manually put the correct zipped tor binary into the resources.

To use tor we need to change the supportedTransportTypes = ["CLEAR"] to supportedTransportTypes = ["TOR"] in the android.config file.

As Tor support is not a must-have in the MVP scope this task has lower priority, though I think a time-boxed effort might be worth it, and if it turns out that Tor is working without lot of additional effort it would be a great achievement.