Long-press on an app to reveal its shortcuts.

- Add ShortcutsContainerListener to icons on workspace, folders, and
  all apps. This handles long-press and forwards following touches to
  the DeepShortcutsContainer that is created.
- Drag over shortcut before lifting finger to launch it.
- Shortcuts are rendered in pill-shaped DeepShortcutViews,
  which are inside DeepShortcutContainer on DragLayer.
- The shortcut container orients above or below the icon, and left or
  right-aligns with it. Biases for above + left-align.
- Long press a DeepShortcutPill to drag and pin it to the workspace.

Bug: 28980830
Change-Id: I08658d13ae51fe53064644e8d8f7b42f150fdd7d

src/com/android/launcher3/BubbleTextView.java

@@ -67,6 +67,7 @@ public class BubbleTextView extends TextView
     private final Launcher mLauncher;
     private Drawable mIcon;
     private final Drawable mBackground;
+    private OnLongClickListener mOnLongClickListener;
     private final CheckLongPressHelper mLongPressHelper;
     private final HolographicOutlineHelper mOutlineHelper;
     private final StylusEventHelper mStylusEventHelper;
@@ -270,6 +271,16 @@ public class BubbleTextView extends TextView
         }
     }
 
+    @Override
+    public void setOnLongClickListener(OnLongClickListener l) {
+        super.setOnLongClickListener(l);
+        mOnLongClickListener = l;
+    }
+
+    public OnLongClickListener getOnLongClickListener() {
+        return mOnLongClickListener;
+    }
+
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         // Call the superclass onTouchEvent first, because sometimes it changes the state to