[SF] Update DeviceProductInfo on hotplug reconnect

This change populates DeviceProductInfo on hotplug, even if we are
in legacy multi-display mode. This behaviour is guarded by sysprop
ro.surface_flinger.update_edid_on_hotplug_reconnect which is
turned off by default.

Bug: 160952291
Test: 1. connect display
      2. adb shell dumpsys SurfaceFlinger | grep deviceProductInfo
      3. connect different display
      4. adb shell dumpsys SurfaceFlinger | grep deviceProductInfo
      5. make sure DeviceProductInfo has changed.

Change-Id: I94751f678b1dd1196727ad38ab5e398fb6cf0393
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.h b/services/surfaceflinger/SurfaceFlingerProperties.h
index c63adfe..37a6b40 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.h
+++ b/services/surfaceflinger/SurfaceFlingerProperties.h
@@ -95,6 +95,9 @@
 int32_t display_update_imminent_timeout_ms(int32_t defaultValue);
 
 android::ui::DisplayPrimaries getDisplayNativePrimaries();
+
+bool update_device_product_info_on_hotplug_reconnect(bool defaultValue);
+
 } // namespace sysprop
 } // namespace android
 #endif // SURFACEFLINGERPROPERTIES_H_