DOC-3141: Update upgrade.adoc with CRR and backup instructions#912

Tushar-TG-14 wants to merge 1 commit into4.2tigergraph/server-docs:4.2from

DOC-3141-updated-upgrading-a-crr-system-4.2]tigergraph/server-docs:DOC-3141-updated-upgrading-a-crr-system-4.2]Copy head branch name to clipboard