Notify readers about participant internal writers

Previously, readers didn't get liveliness updates on writers within
the same participant using the automatic lifetime. This caused
instances to get disposed, even if the writer was still alive.

This change notifies the local readers in the similiar way as this
is the case for readers on a different participant.

Signed-off-by: Philipp Jeske <philipp.jeske@iqsight.com>

Author: pwueje

src/cpp/rtps/builtin/liveliness/WLP.cpp

@@ -844,6 +844,13 @@ bool WLP::automatic_liveliness_assertion()
 
     if (0 < automatic_writers_.size())
     {
+        if (automatic_readers_)
+        {
+            sub_liveliness_manager_->assert_liveliness(
+                dds::AUTOMATIC_LIVELINESS_QOS, 
+                mp_participant->getGuid().guidPrefix);
+        }
+
         lock.unlock();
         return send_liveliness_message(automatic_instance_handle_);
     }