Adding initial TRON logging for picture-in-picture.

Bug: 33756317
Test: Run PIP activity
Change-Id: Iad270dfdf6521d4659653a0697effaed4a0d4137
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 83a786f..5175e80 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -163,6 +163,8 @@
 import android.view.Surface;
 
 import com.android.internal.content.ReferrerIntent;
+import com.android.internal.logging.MetricsLogger;
+import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.internal.os.TransferPipe;
 import com.android.internal.statusbar.IStatusBarService;
 import com.android.internal.util.ArrayUtils;
@@ -2278,6 +2280,8 @@
                         // pinned stack is recreated. See moveActivityToPinnedStackLocked().
                         task.setTaskToReturnTo(isFullscreenStackVisible && onTop ?
                                 APPLICATION_ACTIVITY_TYPE : HOME_ACTIVITY_TYPE);
+                        MetricsLogger.action(mService.mContext,
+                                MetricsEvent.ACTION_PICTURE_IN_PICTURE_EXPANDED_TO_FULLSCREEN);
                     }
                     moveTaskToStackLocked(tasks.get(i).taskId,
                             FULLSCREEN_WORKSPACE_STACK_ID, onTop, onTop /*forceFocus*/,