Michael Strahan has opened up about his daughter’s battle with cancer. The NFL star-turned-television host and his 19-year-old daughter Isabella revealed in a Thursday interview with Strahan’s “Good Morning America” co-anchor Robin Roberts that Isabella had been diagnosed with a malignant brain tumor. “I literally think that in a lot of ways, I’m the luckiest man in the world because I’ve got an amazing daughter,” Strahan said. “I know she’s going through it, but I know that we’re never given more than we can handle and that she is going to crush this.” Isabella said she first noticed somethin…