Automatic merge from submit-queue (batch tested with PRs 53234, 53252, 53267, 53276, 53107). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
add get alpha backend service into cloud provider
```release-note
NONE
```