Correctly prevent the bubble screenshot menu when setting missing.

Fixes: 146437754

Test: Manual. With setting disabled, long-press on bubbles does nothing. With setting enabled (adb shell settings put secure allow_bubble_screenshot_menu 1), long press shows the screenshot menu.
Change-Id: Ic48749b0377e41ed06daf6742a7cc08e64e1db5f
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleTouchHandler.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleTouchHandler.java
index 995b35f..fdeaf1f 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleTouchHandler.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleTouchHandler.java
@@ -134,7 +134,8 @@
                 if (isStack) {
                     mViewPositionOnTouchDown.set(mStack.getStackPosition());
                     mStack.onDragStart();
-                    if (!mStack.isShowingBubbleMenu() && !mStack.isExpanded()) {
+                    if (!mStack.isShowingBubbleMenu() && !mStack.isExpanded()
+                            && BubbleExperimentConfig.allowBubbleScreenshotMenu(mContext)) {
                         mShowBubbleMenuRunnable = mStack::showBubbleMenu;
                         mStack.postDelayed(mShowBubbleMenuRunnable,
                                 ViewConfiguration.getLongPressTimeout());