Dynamic Branches do not work with Strict Variant Matching

Strict Variant Matching always fails when using Dynamic Branches instead of other types of keywords.

I've made a simple repro project, with Strict Variant Matching enabled, where I have a simple shader (Stripped down to almost nothing from the URP Lit shader) and two boxes in a scene. In the shader I have a define (USE_DYNAMIC) to switch between using a dynamic branch or multi compile for the three Fog keywords.

Expected results are:

• Fog disabled: RED
• Fog enabled with USE_DYNAMIC disabled: BLUE
• Fog enabled with USE_DYNAMIC enabled: GREEN

In the editor everything works fine but if the define is set to 1 and you make a build and run, Strict Variant Matching will fail and render the boxes in magenta.