take a snapshot of all built Fuchsia packages
usage: fx save-package-stats [--build] [[--name|-n NAME] | [OUTPUT_PATH]]
Save a snapshot of metadata of all Fuchsia packages for later analysis.
--build Build the current package snapshot before saving it
--name|-n NAME Set the NAME of the package snapshot (Default: "system")
OUTPUT_PATH Write the snapshot at the specified OUTPUT_PATH (Default: $FUCHSIA_BUILD_DIR/snapshots/$NAME.snapshot)