mat-autocomplete autoActiveFirstOption sets aria-activedescendant when the autocomplete panel is closed

[ezettersten]

What is the expected behavior?

When the autocomplete panel is closed and autocomplete is autoActiveFirstOption enabled, the input should not have an aria-activedescendent attribute associated to it.

What is the current behavior?

With autoActiveFirstOption attribute added to mat-autocomplete, even when the panel is closed the autocomplete input has aria-activedescendant="[first-mat-option]"

What are the steps to reproduce?

https://stackblitz.com/edit/angular-nsonvp

1. Focus into the autocomplete input.
2. Blur away from the autocomplete input.
3. inspect the input, you should see aria-activedescendant="mat-option-0" on the input element.

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

"@angular/material": "7.1.1"
"@angular/core": "7.1.2"
"@angular/cdk": "7.1.1"
"@angular/cli": "~7.0.2"

Is there anything else we should know?

[angular-automatic-lock-bot]

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