Helm chart that contains annotation with regex of '[0-9] +e [0-9]' will break the index.yaml

Problem description:

Deploying helm chart that contains an annotation with a certain regex (pattern of '[0-9] +e [0-9]' was tested), will break the index.yaml and the repository cannot be used by the helm client until the relevant chart is deleted.

Steps to reproduce:

1. Create a local Helm repository and add it to a virtual repository.
2.  Deploy a chart to the local repository.
3.  Deploy another chart to the local repository which contains the following annotation (as an example) in the Chart.yaml:

annotations:
  revision: "96e29"

1.  Run helm repo update command against the virtual repository.

The command will fail with the below error on the client side:

error unmarshaling JSON: while decoding JSON: json: cannot unmarshal number into Go struct field ChartVersion.entries.annotations of type string

Checking the index.yaml file of the local repository in Artifactory, the annotation is stripped from the quotes.

In the virtual repository the value is converted from String to float:

annotations: 
  revision: 9.6E30

The workaround is to delete the affected chart from the local repository.