Track MimeMap moving to libcore.content.type.

Another CL in this topic moves libcore.net.MimeMap to package
libcore.content.type. This CL updates associated references.

Bug: 136256059
Bug: 124232146
Test: Treehugger
Test: CtsMimeMapTestCases
Change-Id: I60fceae7b0d1ed00896e8f3796616d6c89bb244f
1 file changed