aomdec.sh : Make this test create files if needed to test decoder.

If test files don't already exist it calls aomenc to create them.

cherry-picked #ee9ac321 from aom/master

Change-Id: I0e0f33cb60b3492e9106d6c9e2c51f64f71ebb63
diff --git a/test/tools_common.sh b/test/tools_common.sh
index 97cf272..797c664 100755
--- a/test/tools_common.sh
+++ b/test/tools_common.sh
@@ -322,10 +322,10 @@
   if [ "$(av1_encode_available)" = "yes" ]; then
     local readonly output="$1"
     local readonly encoder="$(aom_tool_path aomenc)"
-
+    shift
     eval "${encoder}" $(yuv_raw_input) \
       --codec=av1 \
-      --ivf \
+      $@ \
       --limit=5 \
       --output="${output}" \
       ${devnull}