gralloc: Add metadata type buffer_type

CRs-Fixed: 2730864
Change-Id: I8f96b5dc905f1b8cedc498d3853be27a8f92ae58
diff --git a/gralloc/QtiGralloc.cpp b/gralloc/QtiGralloc.cpp
index aab5754..903ccba 100644
--- a/gralloc/QtiGralloc.cpp
+++ b/gralloc/QtiGralloc.cpp
@@ -202,6 +202,8 @@
       return MetadataType_StandardMetadataStatus;
     case QTI_VENDOR_METADATA_STATUS:
       return MetadataType_VendorMetadataStatus;
+    case QTI_BUFFER_TYPE:
+      return MetadataType_BufferType;
     default:
       return MetadataType_Invalid;
   }
@@ -291,6 +293,10 @@
     case QTI_VENDOR_METADATA_STATUS:
       err = decodeMetadataState(bytestream, (bool *)param);
       break;
+    case QTI_BUFFER_TYPE:
+      err = static_cast<Error>(android::gralloc4::decodeUint32(
+          qtigralloc::MetadataType_BufferType, bytestream, (uint32_t *)param));
+      break;
     default:
       param = nullptr;
       return Error::UNSUPPORTED;