FPII-2464 : [Part 3/3]  Elevation of privilege vulnerability in Mediaserver CVE-2016-6704 A-30229821

An invalid replySize in effect_descriptor_t gVisualizerDescriptor in the visualizer effect could lead to the possibility of a heap overflow.
The fix is designed to add validation checks to prevent the overflow.

Change-Id: I3b436f2023a70ad26a2e9ab916cb16fa51a4854e
diff --git a/audio_effects/include/audio_effects/effect_visualizer.h b/audio_effects/include/audio_effects/effect_visualizer.h
index cfd99f5..fe46d7f 100644
--- a/audio_effects/include/audio_effects/effect_visualizer.h
+++ b/audio_effects/include/audio_effects/effect_visualizer.h
@@ -41,6 +41,7 @@
 
 #define MEASUREMENT_IDX_PEAK 0
 #define MEASUREMENT_IDX_RMS  1
+#define MEASUREMENT_COUNT 2
 
 /* enumerated parameters for Visualizer effect */
 typedef enum