Problem exists on Master (0251f6303b) and goes as far back as the "Cull Mode" option existed (6.9.1 release)

Repro steps:
1. Create a new HD Unlit Shadergraph
2. Open settings
3. Switch "Surface Type" to Transparent. Observe lack of "Cull Mode" Option
4. Check "Double Sided"
5. Switch Surface Type to Opaque, then back to Transparent
6. Observe new "Cull Mode" option

Expected result: "Cull Mode" should be available only when "Double Sided" is not checked (this is the case on the material, but not on the shadergraph). Additionally, you should not have to switch Surface Type to get it to appear and disappear. If this can not be done for infrastructural reasons, at the very least, Cull Mode should be available only when Double Sided is not checked; right now, it's backwards.

Actual result: "Cull Mode" only appears after checking "Double Sided" and then switching to Transparent.