Unit tests failing on Windows Environment

Due to the recent upgrade from junit 4 to junit 5 ,it has been noted that there are some unit tests failing in core for windows environment that need to be fixed.

The logs: https://pastebin.com/UstUVqHk

Talkthread:https://talk.openmrs.org/t/tests-failing-in-core-on-windows/29471

The tests are

 saveObs_shouldRetrieveCorrectMimetype

in

BinaryStreamHandlerTest class

and

saveObs_shouldRetrieveCorrectMimetype

in

MediaHandlerTest class