update to latest version of libadb

@ochameau: this updates the version of libadb that `make LIBADB_LOCATION=remote` downloads from 0.3 to 0.4, which is the latest version of the library. There are no code changes here, because the code in android-tools/ is already up-to-date, so `make LIBADB_LOCATION=local` already builds the latest version locally. This merely updates the build variable.

Note that @bkase and I also recently reviewed and merged @brendandahl's fixes for that Windows crasher. But those changes are all in JS, so they don't require rebuilding the library. We still have a performance/CPU utilization issue with the wait timer on Windows, and we need to work out the library lifecycle issues, but then we should be ready to advertise libadb to a larger audience and get folks using it!