### What changes were proposed in this pull request?
Fail the celeborn master/worker start if `CELEBORN_CONF_DIR` is not directory. Otherwise, the process would run into unexpected status.
### Why are the changes needed?
In the `celeborn-daemon.sh` , if we specify the `--config <conf-dir>` option. It would fail the master/worker start if the `conf-dir` is not a directory, likes the systemctl `ConditionPathExists=$CELEBORN_CONF_DIR` requirement check.
fde6365f68/sbin/celeborn-daemon.sh (L35)fde6365f68/sbin/celeborn-daemon.sh (L53-L62)
But before this PR, for the start master/worker scripts, it did not check if the `CELEBORN_CONF_DIR` is dirctory because the scripts did not leverage `--config <conf-dir>` option.
In this PR, we check the final `CELEBORN_CONF_DIR` before start celeborn, so that all the scripts would check if the `CELEBORN_CONF_DIR` is a directory before start.
### Does this PR introduce _any_ user-facing change?
Yes, it would fail the start if `CELEBORN_CONF_DIR` is not a directory.
### How was this patch tested?
<img width="840" alt="image" src="https://github.com/user-attachments/assets/e670d21b-cb01-4fa6-8a2f-c94dc06cce4a" />
Closes#3030 from turboFei/check_config_dir.
Authored-by: Wang, Fei <fwang12@ebay.com>
Signed-off-by: mingji <fengmingxiao.fmx@alibaba-inc.com>
1b3bd6eb38