Automatic merge from submit-queue

Convert deprecated gcloud --regexp flag into --filter

**What this PR does / why we need it**: #49673 missed a flag in hiding:
```console
WARNING: Flag --regexp is deprecated. Use --filter="name~'REGEXP'" instead.
ERROR: gcloud crashed (TypeError): 'NoneType' object is not iterable

If you would like to report this issue, please run the following command:
  gcloud feedback

To check gcloud for common problems, please run the following command:
  gcloud info --run-diagnostics
```

(Also it's great how gcloud crashes, rather than handling the deprecation gracefully.)

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #49673

**Release note**:

```release-note
NONE
```

cc @pci