SF: Introduce a configure stage

Decouple hotplug processing from commit of display transactions, as a
step toward per-display commit/composite. The configure stage will be
responsible for mode setting as well.

Bug: 241285876
Test: libsurfaceflinger_unittest
Change-Id: I72b7223760fa5896debb046f158845a0b4f4599a
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 4730493..eb3856d 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -116,6 +116,7 @@
     using Impl::getScheduledFrameTime;
     using Impl::setDuration;
 
+    using Impl::scheduleConfigure;
     using Impl::scheduleFrame;
 
     // Schedule an asynchronous or synchronous task on the main thread.