SAN FRANCISCO—Cruise ships are returning to San Francisco after a 19-month hiatus brought on by the coronavirus pandemic. Mayor London Breed announced the Majestic Princess will sail into the port of San Francisco on Monday. It’s the first cruise ship to dock in the San Francisco Bay Area since March 2020, when the Grand Princess captured the world’s attention. The ship was carrying people infected with the coronavirus, and thousands on board were quarantined as it idled off the California coast. The Majestic Princess will sail from Los Angeles for a weeklong California coast voyage that will include an overnight stop in San Francisco. The port of San Francisco expects to welcome 21 cruise ships through the remainder of the year. Passengers will have to show they were vaccinated at least 14 days before embarking on the cruise and have proof of vaccination. They must also have a negative COVID-19 …