Removing some unused method params from CellLayout

> Replacing various distance calculations with Math.hypot
> Moving findVacantCell to Utilities

Change-Id: I0cb194b603e52b3bb2b29a095bb4da2bb408ab13
diff --git a/src/com/android/launcher3/DeviceProfile.java b/src/com/android/launcher3/DeviceProfile.java
index 22fb6a0..3dadd1a 100644
--- a/src/com/android/launcher3/DeviceProfile.java
+++ b/src/com/android/launcher3/DeviceProfile.java
@@ -460,8 +460,7 @@
     }
 
     @Thunk float dist(PointF p0, PointF p1) {
-        return (float) Math.sqrt((p1.x - p0.x)*(p1.x-p0.x) +
-                (p1.y-p0.y)*(p1.y-p0.y));
+        return (float) Math.hypot(p1.x - p0.x, p1.y - p0.y);
     }
 
     private float weight(PointF a, PointF b,