Caching avg total bytes and avg free bytes inside ClusterInfo (opense…

…arch-project#14851) (opensearch-project#14892)

(cherry picked from commit 1305002)

Signed-off-by: RS146BIJAY <rishavsagar4b1@gmail.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Signed-off-by: Daniel Widdis <widdis@gmail.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Daniel Widdis <widdis@gmail.com>
Signed-off-by: kkewwei <kkewwei@163.com>