Define OMX_AUDIO_AACObjectER_Scalable

Add enumeration entry and string for ER-AAC-Scalable

Bug 29221608

Change-Id: Ia9309f303ccab19cd863e3a8614468ece7e92b4a
diff --git a/include/media/openmax/OMX_AsString.h b/include/media/openmax/OMX_AsString.h
index 03801ca..a7d1656 100644
--- a/include/media/openmax/OMX_AsString.h
+++ b/include/media/openmax/OMX_AsString.h
@@ -107,6 +107,7 @@
         case OMX_AUDIO_AACObjectLTP:      return "LTP";
         case OMX_AUDIO_AACObjectHE:       return "HE";
         case OMX_AUDIO_AACObjectScalable: return "Scalable";
+        case OMX_AUDIO_AACObjectER_Scalable: return "ER_Scalable";
         case OMX_AUDIO_AACObjectERLC:     return "ERLC";
         case OMX_AUDIO_AACObjectLD:       return "LD";
         case OMX_AUDIO_AACObjectHE_PS:    return "HE_PS";