sdm: comply with treble guidelines

Modify the property names and use macros in place of them

CRs-Fixed: 2206249
Change-Id: I5ae790ca62a258b0d7c14931e0132727feed48a3
diff --git a/gralloc/gr_buf_mgr.cpp b/gralloc/gr_buf_mgr.cpp
index 70fb483..91d9011 100644
--- a/gralloc/gr_buf_mgr.cpp
+++ b/gralloc/gr_buf_mgr.cpp
@@ -42,7 +42,7 @@
   char property[PROPERTY_VALUE_MAX];
 
   // Map framebuffer memory
-  if ((property_get("debug.gralloc.map_fb_memory", property, NULL) > 0) &&
+  if ((property_get(MAP_FB_MEMORY_PROP, property, NULL) > 0) &&
       (!strncmp(property, "1", PROPERTY_VALUE_MAX) ||
        (!strncasecmp(property, "true", PROPERTY_VALUE_MAX)))) {
     map_fb_mem_ = true;