Replicant started maintaining their own version of the SDK because the
binaries you download from Google come with a proprietary license:
https://web.archive.org/web/20130908071448/http://replicant.us/2013/01/replicant-4-0-sdk-release/
http://code.paulk.fr/article0008/what-s-up-with-the-android-sdk
But this stopped not because Google changed their mind but because of Debian:
https://blog.replicant.us/2017/04/there-wont-be-a-replicant-6-0-sdk-because-there-is-already-something-better/
"Would I be right in assuming that the android-sdk in the Trisquel repo is
exactly the same as that found on the Android website?"
I would not say that. Because what you get with Trisquel comes with freedom,
and without the proprietary terms like "you may not ... copy ... modify...
adapt, redistribute, decompile, reverse engineer, disassemble, or create
derivative works of the SDK..."
