Clean up how metrics were disabled

Initially both metrics collection and publishing were
going to be disabled to work around P0:b/35093325.
But disabling collection was not completed since it proved
to be unnecessary. However, remnants were left in the header
file. This change just cleans up the remnants.

Change-Id: Ibdceafd2add31c93de995a558a675b8ba8a055bc
related-to-bug:35093325

libwvdrmengine/cdm/metrics/include/metrics_front_end.h

@@ -40,13 +40,6 @@ class MetricsFrontEnd {
 
 #define NO_TIME 0
 
-#if 0 // Disable metrics for now to work around P0:b/35093325
-
-#define M_RECORD(GROUP, METRIC, TIME, ...)
-#define M_TIME(CALL, GROUP, METRIC, ...)
-
-#else // Re-enable when we have time to debug
-
 #define M_RECORD(GROUP, METRIC, TIME, ...)      \
   if ( GROUP ) { \
     ( GROUP ) -> METRIC . Record( TIME, ##__VA_ARGS__ ); \
@@ -61,6 +54,5 @@ class MetricsFrontEnd {
   } else { \
     CALL; \
   }
-#endif // Disable
 
 #endif