Use taskRootPackageName instead of packageName to load uid when usage

resource is USAGE_SOURCE_TASK_ROOT_ACTIVITY and taskRootPackageName is
not empty.

This logic is consistent with digital wellbeing: assign the screen-on
time onto task root activity when usage resource is
USAGE_SOURCE_TASK_ROOT_ACTIVITY.

Bug: 260964679
Test: make RunSettingsRoboTests + manual
Change-Id: I4c7ed342d8c00951879f5826bf79575f330ce86e

src/com/android/settings/fuelgauge/batteryusage/DataProcessor.java

@@ -256,7 +256,8 @@ public final class DataProcessor {
                             break;
                         }
                         final AppUsageEvent appUsageEvent =
-                                ConvertUtils.convertToAppUsageEvent(context, event, userId);
+                                ConvertUtils.convertToAppUsageEvent(
+                                        context, sUsageStatsManager, event, userId);
                         if (appUsageEvent != null) {
                             numEventsFetched++;
                             appUsageEventList.add(appUsageEvent);