fix: Helm chart name in microservices demo helmrelease

[rossf7]

What type of PR is this?

kind/bug

What this PR does / why we need it:

The microservices demo wasn't deployed because of a typo in the chart name.

k get helmcharts.source.toolkit.fluxcd.io -n falco falco-online-boutique
NAME                    CHART             VERSION   SOURCE KIND      SOURCE NAME       AGE   READY   STATUS
falco-online-boutique   online-boutique   *         HelmRepository   online-boutique   20d   False   chart pull error: failed to get chart version for remote reference: could not get tags for "online-boutique": unable to locate any tags in provided repository: oci://us-docker.pkg.dev/online-boutique-ci/charts/online-boutique

See https://github.com/GoogleCloudPlatform/microservices-demo/tree/main/helm-chart