Cropped Landsat example data warns in documentation due to different pixel interpretation

[rhugonnet]

The example gu.examples.get_path("everest_landsat_b4_cropped") does not have the same pixel interpretation as gu.examples.get_path("everest_landsat_b4") (likely because of the way our old crop() function was overridding the attribute to "Area" when we saved that file, see #127).
This is creating a lot of new warnings in the documentation (for instance here: https://geoutils.readthedocs.io/en/stable/core_lazy_load.html#lazy-passing-of-georeferencing-metadata).

We should probably update it to be the same interpretation to facilitate the documentation example, and update the few tests that relied on that difference to override the attribute back to "Area" before the test.