CPA verification fails for images defined in globals.azure.images section even if syntactically correct

### This issue is for a: (mark with an `x`)
```
- [ X] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce

**NOTE:** I have forked and committed the below changes to a branch [here](https://github.com/nuvious/kubernetes-offer-samples/tree/cpa-bug-with-subcharts) and a diff of the changes can be seen [here](https://github.com/Azure-Samples/kubernetes-offer-samples/compare/main...nuvious:kubernetes-offer-samples:cpa-bug-with-subcharts?expand=1)

```bash
cd samples/k8s-offer-azure-vote
mkdir charts
cd charts
helm create test-subchart-redis
```

Edit `image` section in `samples/k8s-offer-azure-vote/azure-vote/charts/test-subchart-redis/values.yaml` to read:

```yaml
image:
repository: redis
pullPolicy: IfNotPresent
# Overrides the image tag whose default is the chart appVersion.
tag: "alpine"
```

Edit liveness/readiness probes in the `samples/k8s-offer-azure-vote/azure-vote/charts/test-subchart-redis/values.yaml` to read:

```yaml
livenessProbe:
tcpSocket:
port: 6379
initialDelaySeconds: 15
periodSeconds: 10
readinessProbe:
tcpSocket:
port: 6379
initialDelaySeconds: 15
periodSeconds: 10
```

Edit `globals.azure.images` section to read:

```yaml
global:
azure:
images:
frontend:
tag: latest
image: azure-vote-front
registry: azurek8ssamples.azurecr.io/marketplaceimages
backend:
tag: alpine
image: redis
registry: docker.io/library
test-subchart-redis:
tag: alpine
image: redis
registry: docker.io/library
```

**NOTE:** I have also tried putting the `globals.azure.images` definition in the subchart itself but that does not resolve the issue.

Additionally, there are a few places in the generated helm chart where you need/may want to change `nginx` to `redis`. Again, if you clone [the branch in my fork](https://github.com/nuvious/kubernetes-offer-samples/tree/cpa-bug-with-subcharts), I have done this already.

Test helm chart with `helm install azure-vote-with-subchart samples/k8s-offer-azure-vote/azure-vote`. Expected output with kubectl get all:

```bash
drcheese@drcheese-workstation:~/kubernetes-offer-samples$ helm install azure-vote-with-subchart samples/k8s-offer-azure-vote/azure-vote
NAME: azure-vote-with-subchart
# other output from helm chart
kubectl get service -l name=azure-vote-front -w
drcheese@drcheese-workstation:~/kubernetes-offer-samples$ kubectl get app
error: the server doesn't have a resource type "app"
drcheese@drcheese-workstation:~/kubernetes-offer-samples$ kubectl get all
NAME READY STATUS RESTARTS AGE
pod/azure-vote-with-subchart-test-subchart-redis-fd686547c-xsfh9 1/1 Running 0 37s
pod/vote-back-azure-vote-with-subchart-558558cd8d-5hgpm 1/1 Running 0 37s
pod/vote-front-azure-vote-with-subchart-74788c556f-2b88z 1/1 Running 0 37s

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/azure-vote-front LoadBalancer 10.0.30.199 172.183.224.209 80:30733/TCP 37s
service/azure-vote-with-subchart-test-subchart-redis ClusterIP 10.0.77.65 80/TCP 37s
service/vote-back-azure-vote-with-subchart ClusterIP 10.0.34.29 6379/TCP 37s

NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/azure-vote-with-subchart-test-subchart-redis 1/1 1 1 37s
deployment.apps/vote-back-azure-vote-with-subchart 1/1 1 1 37s
deployment.apps/vote-front-azure-vote-with-subchart 1/1 1 1 37s

NAME DESIRED CURRENT READY AGE
replicaset.apps/azure-vote-with-subchart-test-subchart-redis-fd686547c 1 1 1 37s
replicaset.apps/vote-back-azure-vote-with-subchart-558558cd8d 1 1 1 37s
replicaset.apps/vote-front-azure-vote-with-subchart-74788c556f 1 1 1 37s
drcheese@drcheese-workstation:~/kubernetes-offer-samples$
```

Run `cpa verify` with the `samples/k8s-offer-azure-vote` directory as your PWD:

```bash
# cd samples/k8s-offer-azure-vote
docker run -it --rm \
-v /var/run/docker.sock:/var/run/docker.sock \
-v $PWD:/data \
mcr.microsoft.com/container-package-app:latest \
/bin/sh -c "cd /data; cpa verify"
```

### Any log messages given by the failure

```plaintext
CPA Version: 1.3.12
By using the Azure Kubernetes CNAB Packaging Application, you agree to the License contained in the application. You can view the License at ~/LICENSE.
We collect telemetry data, if you would like to opt out of data collection please use the --telemetryOptOut flag.
Correlation Id: aeb883e5-95d6-46f6-b7d0-e4355ab3e4d9
Manifest file validated, 0 total failure(s)

Manifest verification successful.
Helm chart validated, 1 total failure(s)

Container image was invalid: The container image 'docker.io/library/redis:alpine' generated from helm was not listed in the values.yaml file under global.azure.images.
2024/05/21 17:59:53
Correlation Id: aeb883e5-95d6-46f6-b7d0-e4355ab3e4d9, CPABuild: 1.3.12
2024/05/21 17:59:53 Container image was invalid: The container image 'docker.io/library/redis:alpine' generated from helm was not listed in the values.yaml file under global.azure.images.
2024/05/21 17:59:53
For more info refer to the documentation here: https://aka.ms/K8sOfferPrepareAssets#update-the-helm-chart
```

### Expected/desired behavior

Chart is verified. The container referenced is a repeat of previously used syntax so it should be syntactically correct.

### OS and Version?

```bash
drcheese@drcheese-workstation:~/kubernetes-offer-samples/samples/k8s-offer-azure-vote$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.4 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.4 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy
```

### Versions

CPA Version: 1.3.12
Image used when running docker: mcr.microsoft.com/container-package-app:latest (per reference below)

### Mention any other details that might be useful

References used:
https://learn.microsoft.com/en-us/partner-center/marketplace/azure-container-technical-assets-kubernetes?tabs=windows%2Clinux2
**NOTE:** I would have raised this issue with the CPA tool if it had a github but it doesn't seem to. Additionally, the [https://mcr.microsoft.com](https://mcr.microsoft.com) does not seem to have any reference information for this container definition which could point to a project page where this issue could be raise. Happy to re-publish the issue somewhere appropriate if this isn't the right project. Just came here because the above link references this project specifically.