Merge pull request #68796 from ronen-fr/wip-rf-snapreset-crimson

Crimson/osd/snap-mapper: flush pending writes on pg interval change

Reviewed-by: Xuehan Xu <xuxuehan@qianxin.com>
Reviewed-by: Aishwarya Mathuria <amathuri@redhat.com>
Reviewed-by: Matan Breizman <mbreizma@redhat.com>