Fix trampoline activities when relaunching PiP

- We should be checking the actual launched-from package since that stores
  the source package across trampoline activities

Bug: 35458117
Test: Enter PiP from a trampoline activity, launch again from Launcher
      and ensure that it is expanded

Change-Id: Ia0e586e8b21dee63b513bd61a41a24e7da4325e1
diff --git a/services/core/java/com/android/server/am/ActivityStarter.java b/services/core/java/com/android/server/am/ActivityStarter.java
index 4b07af0..7605a1e 100644
--- a/services/core/java/com/android/server/am/ActivityStarter.java
+++ b/services/core/java/com/android/server/am/ActivityStarter.java
@@ -585,10 +585,8 @@
             // The activity was already running in the pinned stack so it wasn't started, but either
             // brought to the front or the new intent was delivered to it since it was already in
             // front. Notify anyone interested in this piece of information.
-            final ComponentName sourceComponent = sourceRecord == null ? null :
-                    sourceRecord.realActivity;
             mService.mTaskChangeNotificationController.notifyPinnedActivityRestartAttempt(
-                    sourceComponent);
+                    sourceRecord.launchedFromPackage);
             return;
         }
     }