Support configurable buffer size for large payload

[ttj4]

Describe what happened:

I have installed the datadog agent with helmchart on my k8s cluster.

For high throughput, I want to set dogstatsd_buffer_size value on the agent as per https://docs.datadoghq.com/developers/dogstatsd/high_throughput/

On the helm chart, I can't see DD_DOGSTATSD_BUFFER_SIZE or dogstatsd_buffer_size variables to pass this info

Describe what you expected:
The helm chart should accept the required variables to see configurable buffer size.

Steps to reproduce the issue:
https://github.com/DataDog/helm-charts/blob/main/charts/datadog/templates/_container-agent.yaml buffer configs are not available in here.

Additional environment details (Operating System, Cloud provider, etc):
NA