Work with java-XYZ/jre and jre-XYZ style alternatives
    
    Fedora recently changed alternatives to use a different
    jdk-based path style. system-switch-java currently assumes
    all JREs are at /usr/lib/jvm/jre-${VERSION}-${VENDOR} but
    recent versions of Fedora put them in a different location,
    /usr/lib/jvm/java-${VERSION}-${VENDOR}-${foo}/jre, which
    breaks system-switch-java.
    
    Detect both of these and use which ever one was originally
    used with alternatives.