SF: Propagate display hotplug errors

Add support for SurfaceFlinger to handle display connection
errors and propagate any error code on hotplug event up the
stack.

Bug: 241286153
Test: manual
Change-Id: I88afeb4f61b13714a81138180db0762cf3ae4ab0
diff --git a/libs/gui/tests/DisplayEventStructLayout_test.cpp b/libs/gui/tests/DisplayEventStructLayout_test.cpp
index 3949d70..29eeaa8 100644
--- a/libs/gui/tests/DisplayEventStructLayout_test.cpp
+++ b/libs/gui/tests/DisplayEventStructLayout_test.cpp
@@ -59,6 +59,7 @@
                  lastFrameTimelineOffset + 16);
 
     CHECK_OFFSET(DisplayEventReceiver::Event::Hotplug, connected, 0);
+    CHECK_OFFSET(DisplayEventReceiver::Event::Hotplug, connectionError, 4);
 
     CHECK_OFFSET(DisplayEventReceiver::Event::ModeChange, modeId, 0);
     CHECK_OFFSET(DisplayEventReceiver::Event::ModeChange, vsyncPeriod, 8);