Adam Sandler just polished off another uncut gem. The man who brought us “The Chanukah Song” premiered his new coronavirus anthem, “Quarantine Song,” on Thursday’s at-home episode of “The Tonight Show Starring Jimmy Fallon.” The “Saturday Night Live” alum’s uplifting, not-totally-parody track pays heartfelt homage to health care workers fighting on the frontlines of the COVID-19 pandemic. “Doctors and nurses will save us from this mess if we get them the supplies that they need — and I hope they save us soon because I’m really, really sick of my family,” Sandler, 53, belted out while wearing some cool mirrored shades “so you can’t see me peeking at my notes so much.” Accompanying himself on electric guitar, Sandler crooned to Fallon,