Revert "Initialize transform tool args when ending stroke"

This reverts commit 8ef04427.

The patch introduces a data-loss in the following usecase:
1) Select transform tool
2) Click on the canvas to activate it
3) Press Enter to apply
4) Click again
5) Press Enter to apply again
4) Click again
5) Press Esc to cancel
6) Click again

The layer data is lost, it becomes completely blank.

CCBUG:415625
(cherry picked from commit dcae8c78)