Add already_in_progress string to roku config flow (#46333)

homeassistant/components/roku/strings.json

@@ -19,6 +19,7 @@
     },
     "abort": {
       "already_configured": "[%key:common::config_flow::abort::already_configured_device%]",
+      "already_in_progress": "[%key:common::config_flow::abort::already_in_progress%]",
       "unknown": "[%key:common::config_flow::error::unknown%]"
     }
   }

homeassistant/components/roku/translations/en.json

@@ -2,6 +2,7 @@
     "config": {
         "abort": {
             "already_configured": "Device is already configured",
+            "already_in_progress": "Configuration flow is already in progress",
             "unknown": "Unexpected error"
         },
         "error": {