Kassia Conway never thought of herself as P. Diddy’s “type.” But with only 48 hours’ notice last winter, she found herself as the main and only musical act at a televised launch party for Diddy’s Revolt TV network. Revolt had already been playing Conway’s self-made video for her first single, “Big Talk,” and previously did a quick bit on the Los Angeles-based artist. Still, she had no idea that Diddy himself was interested. “When I asked who else was playing, they said, ‘It’s just you,'” said Conway, who opens for Ellie Goulding at the Bill Graham Civic Auditorium Saturday. “P. [...]