movesCount seems not be incremented

https://github.com/ashishps1/awesome-low-level-design/blob/60f4f6eb21fcbae4294d6be081b29d2a5172b94b/solutions/java/src/tictactoe/Board.java#L5C23-L5C33

We should increment the **movesCount** variable inside the **placeMove** method, then only the check of isFull() method will be correct.