set DOKKU_APP_TYPE to IMAGE_SOURCE_TYPE value use in test case

plugins/00_dokku-standard/subcommands/receive

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+source "$PLUGIN_AVAILABLE_PATH/config/functions"
 
 dokku_receive_cmd() {
   declare desc="receives an app kicks off deploy process"
@@ -13,6 +14,7 @@ dokku_receive_cmd() {
     dokku_log_info1 "DOKKU_SKIP_CLEANUP set. Skipping dokku cleanup"
   fi
   dokku_log_info1 "Building $APP from $IMAGE_SOURCE_TYPE..."
+  config_set --no-restart "$APP" DOKKU_APP_TYPE="$IMAGE_SOURCE_TYPE" &> /dev/null
   dokku build "$APP" "$IMAGE_SOURCE_TYPE" "$TMP_WORK_DIR"
   release_and_deploy "$APP"
 }