remove metadata fix after next ATL{11,14,15} version up

[JessicaS11]

Per this discussion, ATL11 v006, ATL14 v003, and ATL15 v003 have metadata issues that cause icepyx to fail when it tries to get the version number from the granule file. #516 institutes a temporary fix getting the version from CMR metadata, which should be removed after the next version releases of these products.