Automatic merge from submit-queue (batch tested with PRs 48672, 47140, 48709, 48786, 48757)

use built-in path separator instead of hard coded

**What this PR does / why we need it**:

We should use built-in path separator to avoid hard coded strings.

**Which issue this PR fixes** :

**Special notes for your reviewer**:

**Release note**:

```release-note
None
```