[Android] Adding UMA for events in Background Task Scheduler

components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskJobService.java

Index: components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskJobService.java
diff --git a/components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskJobService.java b/components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskJobService.java
index b53b599ece137673b44a77a5e9314f719d872ef5..a3e6ce49e398d5dd856f8e817b69e4ac66a34db2 100644
--- a/components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskJobService.java
+++ b/components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BackgroundTaskJobService.java
@@ -76,6 +76,8 @@ public class BackgroundTaskJobService extends JobService {
 
         TaskParameters taskParams =
                 BackgroundTaskSchedulerJobService.getTaskParametersFromJobParameters(params);
+
+        BackgroundTaskSchedulerUma.getInstance().reportTaskStarted(taskParams.getTaskId());
         boolean taskNeedsBackgroundProcessing = backgroundTask.onStartTask(getApplicationContext(),
                 taskParams, new TaskFinishedCallbackJobService(this, backgroundTask, params));
 
@@ -96,6 +98,7 @@ public class BackgroundTaskJobService extends JobService {
 
         TaskParameters taskParams =
                 BackgroundTaskSchedulerJobService.getTaskParametersFromJobParameters(params);
+        BackgroundTaskSchedulerUma.getInstance().reportTaskStopped(taskParams.getTaskId());
         boolean taskNeedsReschedule =
                 backgroundTask.onStopTask(getApplicationContext(), taskParams);
         mCurrentTasks.remove(params.getJobId());