IOMX: adding OMX_IndexParamMaxFrameDurationForBitrateControl

Also adding end tag for index groups where we explictly validate.

bug: 31399200
Change-Id: I164ea60258bae809dd4ff389f2480add926a9c4b
diff --git a/include/media/openmax/OMX_AsString.h b/include/media/openmax/OMX_AsString.h
index 4c74bc5..b18fd54 100644
--- a/include/media/openmax/OMX_AsString.h
+++ b/include/media/openmax/OMX_AsString.h
@@ -546,6 +546,8 @@
         case OMX_IndexConfigAndroidIntraRefresh:        return "ConfigAndroidIntraRefresh";
         case OMX_IndexParamAndroidVideoTemporalLayering: return "ParamAndroidVideoTemporalLayering";
         case OMX_IndexConfigAndroidVideoTemporalLayering: return "ConfigAndroidVideoTemporalLayering";
+        case OMX_IndexParamMaxFrameDurationForBitrateControl:
+            return "ParamMaxFrameDurationForBitrateControl";
         case OMX_IndexConfigAutoFramerateConversion:    return "ConfigAutoFramerateConversion";
         case OMX_IndexConfigPriority:                   return "ConfigPriority";
         case OMX_IndexConfigOperatingRate:              return "ConfigOperatingRate";