The MMI build type is still a work in progress, and should not be
expected to build successfully yet, so we haven't committed a LavaMoat
policy to the repository for it yet. The policy update script has been
updated to skip MMI by default for now; we can include it after that
build has reached a point where we are confident it will build
successfully.
Recently in #15468 the name of the scripts task used by the LavaMoat
policy generation script was renamed from `scripts:prod` to
`scripts:dist`, but we neglected to change this name in the LavaMoat
policy generation script itself.
The script task has now been updated so that the script works again,
and the LavaMoat policy generation script has been re-run.
This PR converts `generate-lavamoat-policies.sh` to `.js` using Yargs. This makes it easier to only generate policy files for a specific build type (using the `-t` flag), which is often useful during Flask development. In addition, the `lavamoat:background:auto` scripts are renamed, and the main readme is updated with some useful tips.
Note that `lavamoat:background:auto:dev` is removed and `lavamoat:background:auto` should be used during local development.
