Fix [kv-4] PerformBackupTask possible NPE/Wrong package report.

mCurrentPackage is null when package doesn't exist, which lead test
failed with NPE
Use request.packageName for case BackupTransport.AGENT_UNKNOWN instead

Bug: 77272500

Test: m -j RunFrameworksServicesRoboTests ROBOTEST_FILTER=PerformBackupTaskTest
Change-Id: I27be85f0c3f95e36edd92d0d552189fbcf6952dd
diff --git a/services/backup/java/com/android/server/backup/internal/PerformBackupTask.java b/services/backup/java/com/android/server/backup/internal/PerformBackupTask.java
index ac605b1..90baea0 100644
--- a/services/backup/java/com/android/server/backup/internal/PerformBackupTask.java
+++ b/services/backup/java/com/android/server/backup/internal/PerformBackupTask.java
@@ -528,7 +528,7 @@
                     // we're otherwise fine.  Just drop it and go on to the next as usual.
                     mStatus = BackupTransport.TRANSPORT_OK;
                     BackupObserverUtils
-                            .sendBackupOnPackageResult(mObserver, mCurrentPackage.packageName,
+                            .sendBackupOnPackageResult(mObserver, request.packageName,
                                     BackupManager.ERROR_PACKAGE_NOT_FOUND);
                 } else {
                     // Transport-level failure means we reenqueue everything
diff --git a/services/robotests/src/com/android/server/backup/PerformBackupTaskTest.java b/services/robotests/src/com/android/server/backup/PerformBackupTaskTest.java
index 644ab03..5e90b3f 100644
--- a/services/robotests/src/com/android/server/backup/PerformBackupTaskTest.java
+++ b/services/robotests/src/com/android/server/backup/PerformBackupTaskTest.java
@@ -468,9 +468,6 @@
         verify(agentMock.agent).onQuotaExceeded(anyLong(), anyLong());
     }
 
-    // TODO: Giving NPE at PerformBackupTask:524 because mCurrentPackage is null (PackageManager
-    // rightfully threw NameNotFoundException). Remove @Ignore when fixed.
-    @Ignore
     @Test
     public void testRunTask_whenAgentUnknown() throws Exception {
         // Not calling setUpAgent()