Merge branch '385579-renaming-pipeline-scheduleservice' into 'master'

Rename to Ci::PipelineSchedules::PlayService

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/177203



Merged-by: Max Fan <mfan@gitlab.com>
Approved-by: Ian Baum <ibaum@gitlab.com>
Approved-by: Jennifer Li <jli@gitlab.com>
Approved-by: Max Fan <mfan@gitlab.com>
Co-authored-by: Vlad Wolanyk <vwolanyk@gitlab.com>