Update rook to rev 16 via SR 790202
    
    https://build.opensuse.org/request/show/790202
    by user KGronlund + dimstar_suse
    - Update to v1.2.7 (bsc#1168160):
      * Apply the expected lower PG count for rgw metadata pools (#5091)
      * Reject devices smaller than 5GiB for OSDs (#5089)
      * Add extra check for filesystem to skip boot volumes for OSD configuration (#5022)
      * Avoid duplication of mon pod anti-affinity (#4998)
      * Update service monitor definition during upgrade (#5078)
      * Resizer container fix due to misinterpretation of the cephcsi version (#5073-1)
      * Set ResourceVersion for Prometheus rules (#4528)
      * Upgrade doc clarification for RBAC related to the helm chart (#5054)