Automatic merge from submit-queue (batch tested with PRs 55545, 55548, 55815, 56136, 56185). 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>.
Ensure GCE AlphaFeatureGate initialized
If no config file is specified for the controller-manager,
the GCE CloudConfig.AlphaFeatureGate property is not initialized.
This can cause a panic when checking for alpha features in the GCE
provider.
```release-note
NONE
```
Closes#55544