Merge "PiP: Disable enter-split button when not visible." into sc-v2-dev am: 229448b89e am: 70a599b11b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16415929

Change-Id: I0a7f38826af456bf97032b72a5162b64c45190b0

libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMenuView.java

@@ -189,7 +189,7 @@ public class PipMenuView extends FrameLayout {
         mEnterSplitButton = findViewById(R.id.enter_split);
         mEnterSplitButton.setAlpha(0);
         mEnterSplitButton.setOnClickListener(v -> {
-            if (mMenuContainer.getAlpha() != 0) {
+            if (mEnterSplitButton.getAlpha() != 0) {
                 enterSplit();
             }
         });