bug(cdk Menu / Portal): Portal/Menu isAttached() not working in ShadowDOM

[chladog]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

When CDK Menu is placed in component inside ShadowDom-encapsulated component, the menu trigger does open the menu, but does not toggle it (when it's open then the click doesn't closes it).
I tracked the issue down through cdk Menu -> overlayRef -> PortalOutlet -> isAttached()

Reproduction

Steps to reproduce:

1. Have ShadowDom component
2. Put Angular CDK Menu in this component
3. Try to toggle cdkMenuTriggerFor

Expected Behavior

Should work same as when not in ShadowDom component.

Actual Behavior

cdkMenuTriggerFor inside ShadowDom doesn't toggle Menu.

Here is the stackblitz with reproducted bug:
https://stackblitz.com/edit/angular-ivy-rq5d9a?file=src/app/app.module.ts

Stackblitz is ng 14, but this bug is still there in Angular 15.

Environment

• Angular: 15^
• CDK/Material: 15^

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