Merge pull request #798 from morganchen12/auth2

Fix default value not being passed when allowNewEmailAccounts was disabled

Author: morganchen12

EmailAuth/FirebaseEmailAuthUI/FUIEmailAuth.m

@@ -199,9 +199,11 @@ - (void)signInWithDefaultValue:(nullable NSString *)defaultValue
     }
   } else {
     if ([delegate respondsToSelector:@selector(emailEntryViewControllerForAuthUI:)]) {
-      controller = [delegate passwordSignInViewControllerForAuthUI:self.authUI email:@""];
+      controller = [delegate passwordSignInViewControllerForAuthUI:self.authUI
+                                                             email:defaultValue ?: @""];
     } else {
-      controller = [[FUIPasswordSignInViewController alloc] initWithAuthUI:self.authUI email:nil];
+      controller = [[FUIPasswordSignInViewController alloc] initWithAuthUI:self.authUI
+                                                                     email:defaultValue];
     }
   }