JDK access issue from sparse zone

In the Global zone, there is already a copy of JDK installed (by default
in Solaris 10). All the java links are setup properly in /usr.
However, as this is a sparse zone, /usr is inherited i.e. read-only.
Installing JDK anywhere in the sparse zone, while solves the problem,
will still require the user to change the appropriate links/PATHs/etc to
ensure the right JDK gets called.