Adding fix for host.name field update based on k8s.node.name

[gizas]

Adds the needed resource/hostname processor that will update the host.name field based on k8s.node.name

Before:

After:

Relates:

Closes: https://github.com/elastic/opentelemetry-dev/issues/516 Found in: https://github.com/elastic/opentelemetry-dev/issues/559

[rogercoll]

@lahsivjar @AlexanderWert We first thought that this would be fixed with the elastictrace processor + the corresponding enrichment: https://github.com/elastic/opentelemetry-lib/pull/108

The issue is that the processor only enriches traces, meaning that we cannot use the processor in metrics/logs OTLP pipeline. The configuration changes used in this PR uses the resource processor to do the mapping for any signal type.