test: move TEST-30-ONCLOCKCHANGE setup to static files

The two timezone files are now installed in the global setup. I am not too
happy about this, but it still seems better than to create a completely
separate image just for this.

test/test-functions

@@ -839,6 +839,7 @@ install_config_files() {
     # we want an empty environment
     > $initdir/etc/environment
     > $initdir/etc/machine-id
+
     # set the hostname
     echo systemd-testsuite > $initdir/etc/hostname
     # fstab