helm variable subsitituion issue

when we deploy a microservice using helm charts containing deployment, services, hpa.. some of the variables in the values.yaml are not getting substituted resulting in failed applications.
As an example even though we have project values assigned in values.yaml. we are getting the below error .

helm upgrade --install testuser . --values values-dev.yaml

values-dev.yaml
project: xyz-pqr-abc-def

metadata {
key: "consumer"
value: "projects/{{ .Values.project }}"
}