Ensure HomeScreenGrid steals touches from widgets when folder is open

This closes #147

app/src/main/kotlin/com/simplemobiletools/launcher/views/HomeScreenGrid.kt

@@ -20,6 +20,7 @@ import android.text.TextUtils
 import android.util.AttributeSet
 import android.util.Size
 import android.util.SizeF
+import android.view.MotionEvent
 import android.view.View
 import android.view.animation.DecelerateInterpolator
 import android.view.animation.OvershootInterpolator
@@ -1511,6 +1512,14 @@ class HomeScreenGrid(context: Context, attrs: AttributeSet, defStyle: Int) : Rel
         }
     }
 
+    override fun onInterceptTouchEvent(ev: MotionEvent?): Boolean {
+        return if (currentlyOpenFolder != null) {
+            true
+        } else {
+            super.onInterceptTouchEvent(ev)
+        }
+    }
+
     private fun Canvas.drawItemInCell(item: HomeScreenGridItem, cell: Rect) {
         if (item.id != draggedItem?.id) {
             val drawableX = cell.left + iconMargin