(NBC/Apple/HBO Max/Netflix/Disney + via AP)LOS ANGELES – Bring on the sentimental holiday rom-coms, the chorus of Christmas music specials and the nostalgia of last century’s animated charmers. HOLIDAY HARMONY— “My Gift: A Christmas Special From Carrie Underwood,” now streaming on HBO Max. — “Mariah Carey’s Magical Christmas Special,” Dec. 4, Apple TV+. Music, dancing, animation and surprise guest stars help create what the streaming service promises to be a heartwarming journey with the pop star. Dolly Parton sings hymns, holiday pop classics and tunes from her new album, and shares personal and faith-based Christmas memories.