message: Only fill last cold-start dex if it is not the only one
  Summary: As title. A single cold-start dex likely has performance implications.
diff: @@ -526,7 +526,7 @@ void InterDex::emit_interdex_classes(
  "End marker discovered between background start/end markers");
  TRACE(IDEX, 2, "Terminating dex due to %s", SHOW(type));
  if (end_marker != cold_start_end_marker ||
  - !m_fill_last_coldstart_dex) {
  + !m_fill_last_coldstart_dex || m_end_markers.size() == 1) {
  flush_out_dex(dex_info, *canary_cls);
  *canary_cls = get_canary_cls(dex_info);
  if (end_marker == cold_start_end_marker) {
  