Remove dependencies on FloatMath

See frameworks/base commit 33253a4baa6279f81a73425b49dfb6abe5f5416e
for details.

Bug: https://code.google.com/p/android/issues/detail?id=36199
Change-Id: I928b0bee35467acb2f06f774b8d0e49fc2336795

src/com/android/launcher3/DragController.java

@@ -488,8 +488,7 @@ public class DragController {
         checkTouchMove(dropTarget);
 
         // Check if we are hovering over the scroll areas
-        mDistanceSinceScroll +=
-            Math.sqrt(Math.pow(mLastTouch[0] - x, 2) + Math.pow(mLastTouch[1] - y, 2));
+        mDistanceSinceScroll += Math.hypot(mLastTouch[0] - x, mLastTouch[1] - y);
         mLastTouch[0] = x;
         mLastTouch[1] = y;
         checkScrollState(x, y);