[EBPF] gpu: change name for GPM metric (#46066)

### What does this PR do?

This PR changes the name for the metric we use to emit the GPM metric `GPM_METRIC_SM_UTIL`, as we have found that it doesn't report the same concept.

### Motivation

Accurate metric values.

### Describe how you validated your changes

Tests passing.

### Additional Notes


Co-authored-by: guillermo.julian <guillermo.julian@datadoghq.com>

Author: gjulianm

pkg/collector/corechecks/gpu/nvidia/collector_test.go

@@ -502,7 +502,7 @@ func TestConfiguredMetricPriority(t *testing.T) {
 
 	// Set up the expected metric order. The first collector in the list should have the highest priority over the rest.
 	desiredMetricPriority := map[string][]CollectorName{
-		"sm_active":         {gpm, sampling, ebpf},
+		"sm_active":         {sampling, ebpf},
 		"process.sm_active": {sampling, ebpf},
 	}
 

pkg/collector/corechecks/gpu/nvidia/gpm.go

@@ -43,7 +43,9 @@ var allGpmMetrics = map[nvml.GpmMetricId]gpmMetric{
 		metricType: metrics.GaugeType,
 	},
 	nvml.GPM_METRIC_SM_UTIL: {
-		name:       "sm_active",
+		// Despite the name, this GPM metric returns the percentage of SMs that were in use, not whether any of them were
+		// active in the interval like gr_engine_active does.
+		name:       "sm_utilization",
 		metricType: metrics.GaugeType,
 	},
 	nvml.GPM_METRIC_SM_OCCUPANCY: {