JDK 9 RFR of 8163431: probeContentType/Basic.java fails after changes for JDK-8146215

[Brian Burkhalter]

Please review at your convenience.

Issue:	https://bugs.openjdk.java.net/browse/JDK-8163431
Patch:	http://cr.openjdk.java.net/~bpb/8163431/webrev.00/

Modify the test to allow for multiple possible MIME types for certain extensions for which there is ambiguity. Testing is in progress.

Thanks,

Brian