Bump google.golang.org/grpc from 1.53.0 to 1.56.3 in /concepts/observability-strategy/configurable-monitoring/pocs/tools/metric-gen in the go_modules group across 1 directory

Bump google.golang.org/grpc from 1.53.0 to 1.56.3 in /concepts/observability-strategy/configurable-monitoring/pocs/tools/metric-gen in the go_modules group across 1 directory #51