Feature Flags: use FeatureToggles interface where possible (#85131)

* Feature Flags: use FeatureToggles interface where possible

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

* Replace TestFeatureToggles with existing WithFeatures

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

---------

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

pkg/expr/converter_test.go

@@ -19,7 +19,7 @@ import (
 func TestConvertDataFramesToResults(t *testing.T) {
 	s := &Service{
 		cfg:      setting.NewCfg(),
-		features: &featuremgmt.FeatureManager{},
+		features: featuremgmt.WithFeatures(),
 		tracer:   tracing.InitializeTracerForTest(),
 		metrics:  newMetrics(nil),
 	}

pkg/expr/service_test.go

@@ -138,7 +138,7 @@ func TestDSQueryError(t *testing.T) {
 		cfg:          setting.NewCfg(),
 		dataService:  me,
 		pCtxProvider: pCtxProvider,
-		features:     &featuremgmt.FeatureManager{},
+		features:     featuremgmt.WithFeatures(),
 		tracer:       tracing.InitializeTracerForTest(),
 		metrics:      newMetrics(nil),
 	}