manager: export runOnMainThread helper

This is a static template function to help installation
of a callback to be called once from main thread at next eventloop round.

Issue: #78262
Change-Id: I1c9abcb2f07944f204b85c095cb2b245744ff33f

src/manager.h

@@ -1009,4 +1009,13 @@ class Manager {
         std::map<std::string, std::weak_ptr<video::SinkClient>> sinkMap_;
 };
 
+// Helper to install a callback to be called once by the main event loop
+template<typename Callback>
+static void runOnMainThread(Callback&& cb) {
+    Manager::instance().addTask([=]() mutable {
+        cb();
+        return false;
+    });
+}
+
 } // namespace ring

src/sip/sipvoiplink.cpp

@@ -1244,15 +1244,6 @@ resolver_callback(pj_status_t status, void *token, const struct pjsip_server_add
     getResolveCallbackMap().process((uintptr_t)token, status, addr);
 }
 
-template<typename Callback>
-static void
-runOnMainThread(Callback&& cb){
-    Manager::instance().addTask([=](){
-        cb();
-        return false;
-    });
-}
-
 void
 SIPVoIPLink::resolveSrvName(const std::string &name, pjsip_transport_type_e type, SrvResolveCallback cb)
 {