Ambient occlusion doesn't work on HDRP Materials (Lit) or ShaderGraph materials when the Specular Occlusion is set to Off.

Repro steps:
- Create a new HDRP Material
- Make sure you have bright visible ambient lighting in your scene.
- Assign a mask map (a white gradient for example) to set the ambient occlusion of the material.
- Put the material on an object in the scene, and play with the ambient occlusion remap slider
- Notice that it changes correctly
- Disable the Specular Occlusion in the material advanced settings
- Ambient Occlusion doesn't work anymore

Alternative repro with ShaderGraph:
- Create a new Lit ShaderGraph and exposed a slider between 0 and 1 connected to the ambient occlusion block.
- Create a new Material from this ShaderGraph and play with the slider you exposed.
- Notice that nothing changes.
- When you set Specular Occlusion to "From AO" in the ShaderGraph it fixes the issue.