Create arc-versions.sh for tag arc-2020.03-rc1

Author: wangnuannuan

arc-versions.sh

@@ -73,7 +73,7 @@ done
 # That should be a separate variable to allow for a straightforward creation of
 # new releases, where we want default to point to release, instead of dev
 # branch.
-default_toolchain_config=arc-2020.03-eng002
+default_toolchain_config=arc-2020.03-rc1
 
 # Specify the default versions to use as a string <tool>:<branch>. Those are
 # taken from the checkout configuration file. Only actually matters if