PlatformException(PlatformException(错误,尝试调用虚拟方法'void com.google.firebase.auth.FirebaseAuth.zza(java.lang.String,long,java.util.concurrent.TimeUnit,com.google.firebase。 auth.PhoneAuthProvider $ OnVerificationStateChangedCallbacks,android.app.Activity,java.util.concurrent.Executor,boolean)'on null object reference,null))