Fix occlusion/partial occlusion calculations.

Was comparing the layers the wrong way round for occlusion (arbitrary for "layerOverlaps" but have flipped the comparison for consistency with the occluded and covered checks).

Bug: 328547358
Test: npm run test:unit:ci
Change-Id: Ia332a3ee403cd8d8fa7af3e835732545cdc6adef
2 files changed