Track libcore update of Map classes to jdk8u60

This adds the api/test-current.txt changes corresponding to
http://r.android.com/238640

This CL requires base CLs, which will get merged from aosp-master,
in order to build.

Change-Id: I0aa2e9c4c7b3b6af79c9885e7e0fdde8880e71c8