Alias Patterns
Format the legend keys any way you want by using alias patterns.

Example: {{metric.name}} - {{metric.label.instance_name}}

Result: cpu/usage_time - server1-europe-west-1

Patterns:
{{metric.type}} = metric type e.g. compute.googleapis.com/instance/cpu/usage_time
{{metric.name}} = name part of metric e.g. instance/cpu/usage_time
{{metric.service}} = service part of metric e.g. compute

{{metric.label.label_name}} = Metric label metadata e.g. metric.label.instance_name
{{resource.label.label_name}} = Resource label metadata e.g. resource.label.zone