Verify OpenJDK 8u121 java.nio: Various

Reverted numerous unnecessary whitespace differences.

Added change marker to MappedByteBuffer and FileSystem.

Imported javadoc fix to ServerSocketChannel.

Bug: 35910877
Test: Build
Change-Id: If15f7c3d0dce79c913c167aa5720def9d8e9b5cb
4 files changed