Mongo Operator and ARM

Hi, change the images tag to multi and disable updateStrategy:

https://hub.docker.com/r/percona/percona-server-mongodb/tags?page=&page_size=&ordering=&name=multi

image:
  repository: percona/percona-server-mongodb
  tag: 6.0.15-12-multi

backup:
  enabled: true
  image:
    repository: percona/percona-backup-mongodb
    tag: 2.4.1-multi