Adjust default xmx/xms configuration

Created by: daniel-hutao

Signed-off-by: Daniel Hu farmer.hutao@outlook.com

The jvm heap memory configuration should maintain about 70-80% of the k8s resource request/limit. Too high is easy to oom, and too low will cause memory waste.

see also: https://akobor.me/posts/heap-size-and-resource-limits-in-kubernetes-for-jvm-applications