[charts/gateway] OTK 4.6.3 release

Description of the change

Changes(documentation only) related to OTK release 4.6.3

Benefits

Drawbacks

Applicable issues

Additional information

Checklist

[X] Chart version bumped in Chart.yaml according to semver.
[X] Variables are documented in the README.md
[X] Title of the PR starts with chart name (e.g. [charts/gateway])
[X] If the chart contains a values-production.yaml apart from values.yaml, ensure that you implement the changes in both files

CAAPIM / apim-charts