MakeSureMapNameIsValid can return other assets if the name matches an Engine Content asset

MakeSureMapNameIsValid will take in a FString, look for an asset matching that FString and edit it to match the asset path of the asset found. This issue is caused by the function not limiting its search to .umap files. This issue only occurs if the map name is the same as an asset in Engine Content.

Regression?: No
This also occurred in 4.14

1. Download/unzip/compile/open the attached project
2. Press play
   Result: The asset path output points to an audio asset in Engine Content rather than the Level (.umap) of the same name
   Expected: The asset path output matches the level of the same name