Revert to changing directory to package symbols (#13790)
Summary of the issue:
The server expects the symbols archive to be structured as ./*.ex_ not ./symbols/*.ex_.
Due to changes in #12540, the symbols archive has been restructured to ./symbols/*.ex_.
This is because 7zip structures the archive based on relative paths.
Description of how this pull request fixes the issue:
Reverts the 7zip symbol build to the old behaviour
