commonsys-intf: display: Fix ContentLightLevel max avg light lvl

- The field minPicAverageLightLevel is actually maxPicAverageLightLevel
  from the H.265 spec, mention it will be deprecated.
- Add new member maxPicAverageLightLevel which clients must use, this
  is same as maxFrameAverageLightLevel from CTA-861.G
- The unit for maxPicAverageLightLevel is 1 cd/m^2.

Change-Id: Ida73949d4e4595bc4505e7451c40c6e6976bd092
CRs-fixed: 2607978
diff --git a/include/color_metadata.h b/include/color_metadata.h
index 25dc5b5..c8a5890 100644
--- a/include/color_metadata.h
+++ b/include/color_metadata.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
+* Copyright (c) 2016-2018, 2020 The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -112,7 +112,8 @@
 typedef struct ContentLightLevel {
   bool     lightLevelSEIEnabled;
   uint32_t maxContentLightLevel;  // unit: cd/m^2.
-  uint32_t minPicAverageLightLevel;  // unit: 1/10000 cd/m^2.
+  uint32_t minPicAverageLightLevel;  // unit: cd/m^2, will be DEPRECATED, use below
+  uint32_t maxPicAverageLightLevel;  // unit: cd/m^2, its same as maxFrameAvgLightLevel(CTA-861-G)
 } ContentLightLevel;
 
 typedef struct ColorRemappingInfo {