Automatic merge from submit-queue (batch tested with PRs 60236, 60332, 57375, 60451, 57408). 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>.

Adding Data Encryption Key (DEK) Key Encryption Key (KEK) integration…

… tests via KMS Plugin Mock.



**What this PR does / why we need it**:
Adding integration tests between KubeAPI and KMS Plugin.
Concretely, this test verifies the following integration contracts:
1. Raw records in ETCD that were processed by KMS Provider should be prefixed with k8s:enc:kms:v1:grpc-kms-provider-name:
2. Data Encryption Key (DEK) should be generated by envelopeTransformer and passed to KMS gRPC Plugin
3. KMS gRPC Plugin should encrypt the DEK with a Key Encryption Key (KEK) and pass it back to envelopeTransformer
4. The payload (ex. Secret) should be encrypted via AES CBC transform
5. Prefix-EncryptedDEK-EncryptedPayload structure should be deposited to ETCD

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```