fix(neo4j): update the neo4j volume properties

[leeeizhang]

Issue:

• A volume mode for the Neo4j 'data' volume is required. #400

Install dependencies with following issues:

Error: INSTALLATION FAILED: execution error at (datahub-prerequisites/charts/neo4j/templates/_volumeTemplate.tpl:207:23):

A volume mode for the Neo4j 'data' volume is required.

Set volumes.data.mode to one of: "share", "selector", "defaultStorageClass", "volume", "volumeClaimTemplate" or "dynamic".

For details of how to configure volume modes see the Neo4j Helm chart documentation at https://neo4j.com/docs/operations-manual/current/kubernetes

To get up-and-running quickly, for development or testing, use "defaultStorageClass" for a dynamically provisioned volume of the default storage class.

E.g. by adding `--set volumes.data.mode=defaultStorageClass`

That is because the latest neo4j set the 'data' volume as required.

After this fix, the installation is normal in GCP containers.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable)