mediacodec: add disabled mpeg2

Disabled since it's not tested enough.

modules/codec/omxil/mediacodec.c

@@ -486,6 +486,7 @@ static int OpenDecoder(vlc_object_t *p_this, pf_MediaCodecApi_init pf_init)
     case VLC_CODEC_VC1:  mime = "video/wvc1"; break;
     case VLC_CODEC_VP8:  mime = "video/x-vnd.on2.vp8"; break;
     case VLC_CODEC_VP9:  mime = "video/x-vnd.on2.vp9"; break;
+    /* case VLC_CODEC_MPGV: mime = "video/mpeg2"; break; */
     default:
         msg_Dbg(p_dec, "codec %4.4s not supported",
                 (char *)&p_dec->fmt_in.i_codec);