initial WIP to remove freeswitch from media path when not recording or transcribing dial calls

lib/session/call-session.js

@@ -926,6 +926,17 @@ class CallSession extends Emitter {
     };
   }
 
+  async releaseMediaToSBC(remoteSdp) {
+    assert(this.dlg);
+    assert(this.dlg.connected);
+    assert(this.ep);
+    assert(typeof remoteSdp === 'string');
+    await this.dlg.modify(remoteSdp);
+    this.ep.destroy()
+      .then(() => this.ep = null)
+      .catch((err) => this.logger.error({err}, 'releaseMediaToSBC: Error destroying endpoint'));
+  }
+
   /**
    * Called any time call status changes.  This method both invokes the
    * call_status_hook callback as well as updates the realtime database