ui5-avatar display in the ui5-shellbar when using an icon displays size too big

[codefactor]

Describe the bug In the case when ui5-avatar is used as a slot in the ui5-shellbar, but we have specified an icon instead of an image - the icon is displayed but the icon seems too big.

To reproduce

1. checkout the repo using similar process like:

   git clone https://github.wdf.sap.corp/xweb/common-components
   git co feature/header
   cd common-components/packages/webcomponents
   npm i
   npm start

   Open http://localhost:8081/test-resources/pages/index.html

the ui5-avatar html is as follows in the example:

<ui5-avatar slot="profile" icon="person-placeholder" initials="CG"></ui5-avatar>

Expected behavior The icon should probably look the same size as the other icons.

Screenshots

Context

• UI5 Web Components version
• OS/Platform: {...}
• Browser (if relevant): {...}
• Other information: {...}

Affected components (if known)

Log output / Any errors in the console

{...}

[codefactor]

It looks like this is controlled through the following attribute.

size="XS"

Closing this ticket now.