Fix crash when clicking fast on back key on the Add account screen.

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/LoginFlowNode.kt

@@ -167,6 +167,10 @@ class LoginFlowNode(
                     override fun navigateToLoginPassword() {
                         backstack.push(NavTarget.LoginPassword)
                     }
+
+                    override fun onDone() {
+                        callback.onDone()
+                    }
                 }
                 val params = inputs<Params>()
                 val inputs = OnBoardingNode.Params(

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/screens/onboarding/OnBoardingNode.kt

@@ -42,6 +42,7 @@ class OnBoardingNode(
         fun navigateToLoginPassword()
         fun navigateToOidc(oidcDetails: OidcDetails)
         fun navigateToCreateAccount(url: String)
+        fun onDone()
     }
 
     data class Params(
@@ -71,7 +72,7 @@ class OnBoardingNode(
             onNeedLoginPassword = callback::navigateToLoginPassword,
             onLearnMoreClick = { openLearnMorePage(context) },
             onCreateAccountContinue = callback::navigateToCreateAccount,
-            onBackClick = ::navigateUp,
+            onBackClick = callback::onDone,
         )
     }
 }