After we port to oslo-incubator.apiclient, the project_id can no
longer be specified for alarm-{,threhsold,combination}-{create,update}
and sample-create, this is because client.AuthPlugin registers a CLI
argument named --os-project-id which will shadow the project-id
argument.
Since os-project-id is used for Keystone V3 API, we should not
remove it from AuthPlugin, so this patch moves the dest of project_id
to {alarm,sample}_project_id, and adds a decorator to restore shadowed
project_id field when we call v2 client.
Change-Id: I0ce2416dccd61eb50584799e6df0b8c45d44cdda
Closes-Bug: #1393489