docs: update java installation doc with JAVA8_HOME details
docs: update java installation doc with JAVA8_HOME details

Summary: SWARM-686

Test Plan: make docs

Reviewers: cwallin, rschlussel

Reviewed By: rschlussel

Differential Revision: https://phabricator.td.teradata.com/D805

Svjard/presto-admin,Svjard/presto-admin,prestodb/presto-admin,prestodb/presto-admin