Forwarding touch events from floating header to recyclerview.

Additionally adds little sidepadding to the tabs buttons and fixes yPos
calculations for the scrollbar.

Bug: 69966700
Change-Id: I9d236ce7a782090f5d17931839f24b65b4ce7019

src/com/android/launcher3/views/RecyclerViewFastScroller.java

@@ -322,7 +322,7 @@ public class RecyclerViewFastScroller extends View {
      * Returns whether the specified point is inside the thumb bounds.
      */
     private boolean isNearThumb(int x, int y) {
-        int offset = y - mRv.getScrollBarTop() - mThumbOffsetY;
+        int offset = y - mThumbOffsetY;
 
         return x >= 0 && x < getWidth() && offset >= 0 && offset <= mThumbHeight;
     }