Build actions can be cached, so they can't be used for Maven
interactions. Instead, generate a script that calls buck and then
runs the upload process.
This obviates tools/maven/api.py.
The script tools/maven/api.sh runs all deployment steps combined
(generate script, generate artifacts, upload to maven.)
Tested:
Ran "python tools/maven/api.py -n deploy" before and "buck
build //tools/maven:gen_api_deploy" afterwards. The old command line
and generated script differ as expected:
* paths in the script are absolute, because Buck expands $(location)
to absolute paths.
* the ordering of arguments differs, because Python dict iteration
was random beforehand.
* "-o" missing afterward, as expected.
The same check was performed for gen_api_install.
Change-Id: Ia246000f8b59e881c53265751e2ebcfe8ec7d433