debian 8: install java-1.8 that's depended by scylla 1.7 and later
debian 8: install java-1.8 that's depended by scylla 1.7 and later

In scylla 1.7, scylla-jmx and scylla-tools depend on java-1.8,

https://github.com/scylladb/scylla/issues/2091

Signed-off-by: Amos Kong <eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>

lmr/scylla-artifact-tests,scylladb/scylla-artifact-tests,scylladb/scylla-artifact-tests