Enabled AV1 decode by default. (#391)

* * rocDecode/AV1: Enabled AV1 decode by default.

* * rocDecode/AV1: Added changes suggested in code review.
 - Bumped up rocDecode version to 0.7.0.
 - Added AV1 support statement in readme file.

[ROCm/rocdecode commit: 96c65d74a6]

projects/rocdecode/src/parser/rocparser_api.cpp

@@ -34,11 +34,10 @@ rocDecCreateVideoParser(RocdecVideoParser *parser_handle, RocdecParserParams *pa
         return ROCDEC_INVALID_PARAMETER;
     }
 
-    const char *is_av1_enabled = std::getenv("ROCDECODE_ENABLE_AV1");
     if (parser_params->codec_type != rocDecVideoCodec_HEVC &&
         parser_params->codec_type != rocDecVideoCodec_AVC &&
-        (parser_params->codec_type == rocDecVideoCodec_AV1 && (is_av1_enabled == nullptr || std::string(is_av1_enabled) != "1"))) {
-        ERR("The current version of rocDecode officially supports only the H.265 (HEVC) and H.264 (AVC) codec.");
+        parser_params->codec_type != rocDecVideoCodec_AV1) {
+        ERR("The current version of rocDecode officially supports only the H.265 (HEVC), H.264 (AVC) and AV1 codecs.");
         return ROCDEC_NOT_IMPLEMENTED;
     }