Issues identified when altering alert content

[hernandezc1]

Altering the content of an alert in Pitt-Google's LSST pipeline(s) (e.g., removing (sub)fields as done in the lite module or adding value to an alert as done in the variability module) creates newly identified issues:

1. The schema_name argument must be set to: default when creating an Alert object as the content no longer conforms to any LSST schema. This is confusing to users as one would reasonable expect to set this value to: lsst.
2. Eliminates ability to use/access the schema map.