Bug 1691841 [wpt PR 27557] - Add WPTs and minor impl fixes for xr light estimation...

Bug 1691841 [wpt PR 27557] - Add WPTs and minor impl fixes for xr light estimation, a=testonly

Automatic update from web-platform-tests
Add WPTs and minor impl fixes for xr light estimation

Adds WPTs around expected behavior for the WebXR Light Estimation spec.
Also corrects a few cases where getReflectionCubeMap should have thrown
an exception but did not currently.

Change-Id: I3e3393c3911a83bdfc91463cf614e04a31dba009
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2685615
Commit-Queue: Alexander Cooper <alcooper@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#852756}

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wpt-commits: 43ead8133543f5d38c0f7aae65770bc1d2e8bad7
wpt-pr: 27557