Const ExperimentalCloudFoundry defines the instance_id in the Loggregator v2 envelope.
It is used for logs and metrics emitted by CloudFoundry. It is
supposed to contain the application instance index for applications
deployed on the runtime.
Application instrumentation should use the value from environment
variable CF_INSTANCE_INDEX.
This attribute is experimental and is subject to breaking changes in minor releases of @opentelemetry/semantic-conventions.
The index of the application instance. 0 when just one instance is active.