[Nav] Custom plugin images that are url's do not display properly in the nav drawer

[cchaos]

Ported from EUI:

---

My implementation is working fine till 7.6.x release. I am facing issue while migrating plugin to 7.7.x. I have attached my plugin screenshot of custom plugin icons. It looks bigger than default EUI icons. As per my analysis 'class="euiIcon euiIcon--medium euiIcon--app euiIcon-isLoaded euiListGroupItem__icon"' is not getting included for custom icon which are implemented using Icon property.

uiExports: {
app: {
title: 'SIP Analyzer',
description: 'An Awesome Kibana SIP Plugin',
main: mainFile,
icon: 'plugins/sip/resource/logo-scaled.png',
}
},

Html tags for custom plugin icon where above mention classes are not includes:

SIP Analyzer

plugin : https://github.com/BroadSoft-Xtended/BroadWorks-Dashboards-and-Discovery/blob/master/SIP-2.4.0_K_7.6.2.zip

Older version :

Originally posted by @parikshitgawali in elastic/eui#1690 (comment)

[cchaos]

I think I narrowed it down to this function

kibana/src/core/public/chrome/ui/header/nav_link.tsx

Lines 31 to 33 in cc893f3

	function LinkIcon({ url }: { url: string }) {
	return <EuiImage size="s" alt="" aria-hidden={true} url={url} />;
	}

EuiIcon supports custom url's as the iconType and so the nav drawer should continue to render it as an EuiIcon. Instead EuiImage with size='s' has an inherit size of 120x120px which is way too large.

[elasticmachine]

Pinging @elastic/kibana-core-ui (Team:Core UI)