USB download on Android (again)

[Dirk Hohndel]

On the off chance that someone happens to have
(a) a recent Android device that doesn't support FTDI downloads with Subsurface
(b) an FTDI dive computer
(c) a cable to connect (b) to (a)
(d) the ability to build for Android locally (which is really easy these
days thanks to the container setup that I've created)
(e) interest and time to figure this out...

A couple of months ago upstream libusb merged the code to wrap Android USB
file descriptors that you can get from JNI which should allow us to work
on recent devices that otherwise fail with libusb.
This thread discusses the pull request that was merged
https://sourceforge.net/p/libusb/mailman/message/36486444/

We already have a helper function to get the file descriptor (get_usb_fd()
in core/android.c). All this should take is to replace our current hack
which involves patching a specific version of libusb (this can be found
in packaging/android/build.sh) with the official mechanism introduced in
libusb master.

Anton may have additional comments - but I know that the one thing he
doesn't have is time...

I will eventually find time to work on this - but that might be a long
while with all the OTHER things I need to work on.

So... anyone?

/D