Resource detection processor sets uppercase values in os.type attribute

[dmitryax]

According to semantic conventions os.type resource attribute has to contain one of the predefined values, all of them are written in lowercase. Resource detection processor sets them in uppercase. It should be changed to lowercase according to semantic conventions

[mx-psi]

Looks like this changed on open-telemetry/opentelemetry-specification#1598

[mx-psi]

Also note that ZOS becomes z_os

[mx-psi]

This amounts to changing this function

opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/resourcedetection.go

Lines 218 to 224 in 36623bc

	func GOOSToOSType(goos string) string {
	switch goos {
	case "dragonfly":
	return "DRAGONFLYBSD"
	}
	return strings.ToUpper(goos)
	}

to do the mapping between GOOS and the spec values.