packaging: setup: enforce java home for pki

pki ca creation script use keytool utility directly, this may use
keytool utility of jdk other than openjdk. as some compatibility issues
were found, use the keytool from the JAVA_HOME we use for our
application.

pki migration to PKCS#12 format also use keytool, apply the same method.

Change-Id: I23ca5bc86cca6e9115a425ff885ab973a4e4135b
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>