This is mostly a brainless merge, #ifdef-ing anything that doesn't match between the two while preserving common logic.  I didn't rename any variables (although similar ones do exist), but I did change one log that was ERROR on android and NOTICE elsewhere to just always be NOTICE.  Further merging will follow.

I am not confident there are no race conditions between s_write_mutex,
s_controller_write_payload_size, and s_controller_write_payload. But
this code should be safer than before.

s_controller_write_payload_size needs to remain an atomic because Read()
loads and stores without holding a mutex, Output() stores while holding
s_write_mutex, and ResetRumble() stores while holding s_read_mutex! I'm
pretty sure this code is wrong, specifically ResetRumble().

SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.

where appropriate. SerialInterface was a leftover from the past,
and makes no sense to be used on actual/real controllers.

Continues the migration of the logging calls over to the fmt capable
ones.

android: get java env from thread local storage