Improve Split portrait gesture animation

* Crop out taskbar from bottom thumbnail for vertical split
* TODO: Need to re-calculate thumbnail sizes if taskbar
 is stashed. There's also a very slight rounding error
 somewhere even in the unstashed case that needs to be
 revisited

Bug: 219411750
Test: Start gesture animation in split in potrait
Change-Id: I35f2415e13af7467e0735ac8865cee0e3e3d27f8

quickstep/src/com/android/quickstep/util/TaskViewSimulator.java

@@ -322,7 +322,7 @@ public class TaskViewSimulator implements TransformParams.BuilderProxy {
             boolean isRtlEnabled = !mIsRecentsRtl;
             mPositionHelper.updateThumbnailMatrix(
                     mThumbnailPosition, mThumbnailData, mTaskRect.width(), mTaskRect.height(),
-                    mDp.widthPx, mDp.taskbarSize, mDp.isTablet,
+                    mDp.widthPx, mDp.heightPx, mDp.taskbarSize, mDp.isTablet,
                     mOrientationState.getRecentsActivityRotation(), isRtlEnabled);
             mPositionHelper.getMatrix().invert(mInversePositionMatrix);
             if (DEBUG) {

quickstep/src/com/android/quickstep/views/TaskThumbnailView.java

@@ -473,8 +473,8 @@ public class TaskThumbnailView extends View {
             boolean isRtl = getLayoutDirection() == LAYOUT_DIRECTION_RTL;
             DeviceProfile dp = mActivity.getDeviceProfile();
             mPreviewPositionHelper.updateThumbnailMatrix(mPreviewRect, mThumbnailData,
-                    getMeasuredWidth(), getMeasuredHeight(), dp.widthPx, dp.taskbarSize,
-                    dp.isTablet, currentRotation, isRtl);
+                    getMeasuredWidth(), getMeasuredHeight(), dp.widthPx, dp.heightPx,
+                    dp.taskbarSize, dp.isTablet, currentRotation, isRtl);
 
             mBitmapShader.setLocalMatrix(mPreviewPositionHelper.getMatrix());
             mPaint.setShader(mBitmapShader);