Do not send setFinishTaskTransaction if not swipe

In PiP2, there is no need to send setFinishTaskTransaction()
unless we are swiping PiP to home.

This is because either ATMS#enterPictureInPictureMode() is supposed
to request a TRANSIT_PIP as the activity goes to pause.

Bug: 380515865
Flag: com.android.wm.shell.enable_pip2
Test: repro the steps in the bug
Change-Id: Ic24c0c0f471179198a5fe3221971cf5b6d634797

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -5906,8 +5906,9 @@ public abstract class RecentsView<
         }
 
         final boolean sendUserLeaveHint = toRecents && shouldPip;
-        if (sendUserLeaveHint) {
+        if (sendUserLeaveHint && !com.android.wm.shell.Flags.enablePip2()) {
             // Notify the SysUI to use fade-in animation when entering PiP from live tile.
+            // Note: PiP2 handles entering differently, so skip if enable_pip2=true.
             final SystemUiProxy systemUiProxy = SystemUiProxy.INSTANCE.get(getContext());
             systemUiProxy.setPipAnimationTypeToAlpha();
             systemUiProxy.setShelfHeight(true, mContainer.getDeviceProfile().hotseatBarSizePx);