Some drivers were missing docs and/or validation for options that
they actually support. This change:
adds launch-timeout to:
metastatic docs and validation
aws validation
gce docs and validation
adds post-upload-hook to:
aws validation
adds boot-timeout to:
metastatic docs and validation
adds launch-retries to:
metastatic docs and validation
Change-Id: Id3f4bb687c1b2c39a1feb926a50c46b23ae9df9a