drm_hwcomposer: Set HDR metadata on the connector

Implement a function to set HDR metadata on the connector. Support HDR10
and HLG, which are common HDR types.

Change-Id: Id3dbe8eea2ee6b8ba700af23845a43e2070dd14e
Signed-off-by: Sasha McIntosh <sashamcintosh@google.com>
diff --git a/drm/DrmConnector.cpp b/drm/DrmConnector.cpp
index 6be4067..37e1be4 100644
--- a/drm/DrmConnector.cpp
+++ b/drm/DrmConnector.cpp
@@ -143,6 +143,9 @@
 
   GetOptionalConnectorProperty("content type", &content_type_property_);
 
+  GetOptionalConnectorProperty("HDR_OUTPUT_METADATA",
+                               &hdr_output_metadata_property_);
+
   if (GetOptionalConnectorProperty("panel orientation", &panel_orientation_)) {
     panel_orientation_
         .AddEnumToMapReverse("Normal",