Fix juttering problem with split staging animation

This patch makes it so that app icons no longer jutter uncomfortably when staging and confirming a split from home.

The problem occurred because I used Math.round when calculating the position at which to center the app icon within the SplitPlaceholderView. When an inexact integer is used to calculate the x and y position on every frame, it creates juttering, especially when numerical values are small.

Solved by removing Math.round and using floats going forward.

Fixes: 262308025
Test: Manual
Change-Id: If91d1d3ee52652c155ed7e4e1d4f4620fdc41cc9

src/com/android/launcher3/touch/LandscapePagedViewHandler.java

@@ -432,10 +432,10 @@ public class LandscapePagedViewHandler implements PagedOrientationHandler {
             int drawableWidth, int drawableHeight, DeviceProfile dp,
             @StagePosition int stagePosition) {
         float insetAdjustment = getPlaceholderSizeAdjustment(dp) / 2f;
-        out.setX(Math.round(onScreenRectCenterX / fullscreenScaleX
-                - 1.0f * drawableWidth / 2));
-        out.setY(Math.round((onScreenRectCenterY + insetAdjustment) / fullscreenScaleY
-                - 1.0f * drawableHeight / 2));
+        out.setX(onScreenRectCenterX / fullscreenScaleX
+                - 1.0f * drawableWidth / 2);
+        out.setY((onScreenRectCenterY + insetAdjustment) / fullscreenScaleY
+                - 1.0f * drawableHeight / 2);
     }
 
     /**