Runtime styling snapshotter tests fail intermittently on CI

[1ec5]

-[MGLMapSnapshotterTests testRuntimeStyling] has failed intermittently on CI ever since #189 (comment). I refactored a helper method to add another snapshotter test that was ultimately disabled; not sure why it causes this test to become unreliable though.

/cc @mapbox/maps-ios

[fabian-guerra]

The current tests draws:
expectedImage as

actualImage_1 as an image with clear color

/cc @1ec5

[1ec5]

I think the culprit is the changes in #189 to test #280. Instead of unconditionally looking at Null Island, the snapshotter is configured to snapshot whatever the style specifies as its default camera. But even in the runs that fail, the style finishes loading, the map transform finishes transitioning to the default camera, and mbgl::Map::Impl::onDidFinishRenderingMap() gets called (which would result in -[MGLMapViewDelegate mapViewDidFinishLoadingMap:] getting called in a map context).

[1ec5]

#293 works around the issue for now, since it’s frequently blocking builds. mapbox/mapbox-gl-native#16454 tracks the likely issue upstream in mbgl.

[captainbarbosa]

This might be happening again...?