Android - Bluetooth connection multiplexer
Summary
Adds the bluetooth connection multiplexer. This means that all transfers go over a single bluetooth connection, making them work reliably.
There are still lots of issues left with bluetooth, but this is a big step forward to me.
Test Plan
Enable the bluetooth backend in src/org/kde/kdeconnect/BackgroundService.java
, add bluetooth permissions (see commit mtijink/kdeconnect-android@6e44b570) and make sure your devices are paired. Connecting is quite slow initially, but should work within a minute. I only managed to get pc -> phone connecting to work, but I think that's unrelated to this work.
If you have trouble, try my bluetooth-extra
branch.