The Sheraton has a free airport shuttle from 4 am until 11 pm. It runs about every 15-20 minutes.
Holland America has used this hotel for more than 15 years.
Princess will have a transfer to/from the Diamond Princess to the Sheraton.
As mentioned by others, this hotel is not convenient for public transfers; however, Uber or taxi to the SD Zoo is inexpensive and a favorite place to spend a pre-cruise day.
David