[REQUIRED] Step 1: Describe your environment

• Xcode version: 12.2
• Firebase SDK version: 6.9.2
• Installation method: CocoaPods
• Firebase Component: Auth

[REQUIRED] Step 2: Describe the problem

With Mac Catalyst when the PhoneAuthProvider.provider().verifyPhoneNumber(:, uiDelegate:, completion:) calls the Safari on Mac opens and the user receives following error:

FIRAuthErrorDomain Code=17058 "The interaction was cancelled by the user." UserInfo={NSLocalizedDescription=The interaction was cancelled by the user., FIRAuthErrorUserInfoNameKey=ERROR_WEB_CONTEXT_CANCELLED}

Steps to reproduce:

1. Run any app with phone auth on Mac OS.
2. Call PhoneAuthProvider.provider().verifyPhoneNumber(:, uiDelegate:, completion:) method with valid phone number

Relevant Code:

PhoneAuthProvider.provider().verifyPhoneNumber(validPhoneNumber, uiDelegate: nil) { ( _, error) in
                    if let error = error {
                        // User receives an error
                        assertionFailure(error.localizedDescription)
                    }
                    ...
                }