SF: Moving EventThread::Connection out of impl class

This is part of Scheduler refactoring. EventThread::Connection should be
a wrapper that translates IDisplayEventConnection into EventThread calls.

Test: SF tests pass.
Bug: 113612090
Change-Id: I2bcf0c45a33638c59f7828085c563dbc52b2d66e
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 8d4514b..9d7dd4d 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -53,14 +53,14 @@
 
     class Connection {
     public:
-        Connection(sp<ConnectionHandle> handle, sp<BnDisplayEventConnection> eventConnection,
+        Connection(sp<ConnectionHandle> handle, sp<EventThreadConnection> eventConnection,
                    std::unique_ptr<EventThread> eventThread)
               : handle(handle), eventConnection(eventConnection), thread(std::move(eventThread)) {}
 
         ~Connection() = default;
 
         sp<ConnectionHandle> handle;
-        sp<BnDisplayEventConnection> eventConnection;
+        sp<EventThreadConnection> eventConnection;
         const std::unique_ptr<EventThread> thread;
     };
 
@@ -79,7 +79,7 @@
     // Getter methods.
     EventThread* getEventThread(const sp<ConnectionHandle>& handle);
 
-    sp<BnDisplayEventConnection> getEventConnection(const sp<ConnectionHandle>& handle);
+    sp<EventThreadConnection> getEventConnection(const sp<ConnectionHandle>& handle);
 
     // Should be called when receiving a hotplug event.
     void hotplugReceived(const sp<ConnectionHandle>& handle, EventThread::DisplayType displayType,