Why adb shell pm list permissions -g OR adb shell cmd package list permissions -g does not list permission group: android.permission-group.SYSTEM_TOOLS

[Learner Lovely]

I defined some permissions and assigned them permission group android.permission-group.SYSTEM_TOOLS in AndroidManifest.xml.

Then I install this app in to a phone.

Here is my question, why there is no result when I run adb shell pm list permissions -g OR adb shell cmd package list permissions -g ?

I suppose those defined permissions should be listed.

Could anyone give me some sign?

Thanks a lot.