Change getSystemAppsAllowlist() returns an empty list instead of null.

Bug: 265751163
Test: presubmit
Change-Id: Ide8b36345b328d5969b764b6c5e1503904e9ecaf

src/com/android/settings/fuelgauge/PowerUsageFeatureProviderImpl.java

@@ -26,6 +26,7 @@ import android.util.SparseIntArray;
 import com.android.internal.util.ArrayUtils;
 import com.android.settingslib.fuelgauge.Estimate;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
 
@@ -83,7 +84,7 @@ public class PowerUsageFeatureProviderImpl implements PowerUsageFeatureProvider
 
     @Override
     public List<String> getSystemAppsAllowlist() {
-        return null;
+        return new ArrayList<>();
     }
 
     @Override