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.