Fix lint errors.

Author: sshropshire

CardPayments/src/main/java/com/paypal/android/cardpayments/CardCallback.kt

@@ -10,4 +10,4 @@ object CardCallback {
         @MainThread
         fun onApproveOrderResult(result: CardResult.ApproveOrder)
     }
-}
+}

CardPayments/src/main/java/com/paypal/android/cardpayments/CardResult.kt

@@ -27,4 +27,4 @@ object CardResult {
         data object Canceled : FinishApproveOrder()
         data object NoResult : FinishApproveOrder()
     }
-}
+}

Demo/src/main/java/com/paypal/android/ui/approveorder/ApproveOrderViewModel.kt

@@ -229,8 +229,8 @@ class ApproveOrderViewModel @Inject constructor(
         cardClient?.removeObservers()
     }
 
-    private fun checkIfApproveOrderFinished(intent: Intent): CardResult.FinishApproveOrder?
-        = authState?.let { cardClient?.finishApproveOrder(intent, it) }
+    private fun checkIfApproveOrderFinished(intent: Intent): CardResult.FinishApproveOrder? =
+        authState?.let { cardClient?.finishApproveOrder(intent, it) }
 
     fun completeAuthChallenge(intent: Intent) {
         checkIfApproveOrderFinished(intent)?.let { approveOrderResult ->