Remove java.nio.channels.* classes without test coverage.

Removed classes come from openJdk 1.7 and were never
implemented before. We lack a testing suite to verify that
they are working correctly. Those clasess might by
re-added in further releases

Bug: 27117463
Change-Id: I0ebd8e46c31992f7db158a6abaaeb2180f36f1cb
38 files changed