Rename java.ClassFileContents request to java.classFileContents
Rename java.ClassFileContents request to java.classFileContents

This is a consequence of https://github.com/gorkem/java-language-server/issues/111

Signed-off-by: Fred Bricon <3278c038c93c729ae96f0d035919e3fb69e9cff7@gmail.com>

gorkem/vscode-java,gorkem/vscode-java