Fix bug where customCriteria was always required

[speige]

The old logic: _instance.options.customCriteria !== null || _instance.options.customCriteria !== undefined
will ALWAYS return true.

[docluv]

I will check on this. I have been making major updates to the library the past few weeks.
I am separating the prompt schedule logic from examining if the PWA can be installed. This falls under the latter piece.