fixes #4931 - content view errata by date/type rule - default types to false

This minor change is so that the UI will not always show the
types (enhancement, security, bugfix) as selected/checked.
In other words, the default value is unselected and then overriden
based on the types retrieved from the server.
Merge pull request #3908 from bbuckingham/issue-4931

fixes #4931 - content view errata by date/type rule - default types to false