emailPasswordAuth -> emailPassword refactor (#510)

Author: nathan-contino-mongo

source/includes/steps-tutorial-android-kotlin.yaml

@@ -800,7 +800,7 @@ content: |
 
             if (createUser) {
                 // register a user using the Realm App we created in the TaskTracker class
-                taskApp.emailPasswordAuth.registerUserAsync(username, password) {
+                taskApp.emailPassword.registerUserAsync(username, password) {
                     // re-enable the buttons after user registration completes
                     createUserButton.isEnabled = true
                     loginButton.isEnabled = true