Update outdated Chrome documentation link in WP_Site_Icon

[mayur8991]

The WP_Site_Icon class contains a reference to an outdated Chrome documentation URL:

​https://developer.chrome.com/multidevice/android/installtohomescreen

This URL is no longer available and returns an error when accessed.

The reference is located in wp-admin/includes/class-wp-site-icon.php in the comment for the 192px Android/Chrome site icon size:

@link ​https://developer.chrome.com/multidevice/android/installtohomescreen

The documentation reference was originally added to document Android/Chrome app icon support, but the linked Chrome documentation is no longer available at this location.

The outdated URL should be updated to an appropriate current Chrome/Android documentation reference, or removed if no suitable replacement exists.

[harishtewari]

@mayur8991 I think ​https://developer.chrome.com/blog/support-for-theme-color-in-chrome-39-for-android should replace this URL

[sabernhardt]

[33202] added the links.

#32964 referred to the ​Icon section of that page, which listed old fallback options.

I think ​https://developer.chrome.com/blog/support-for-theme-color-in-chrome-39-for-android should replace this URL

The first link redirects to this URL now, and it shows the recommended <link> tag. It probably should replace both URLs in the comment.

https://core.trac.wordpress.org/ticket/65940

Trac ticket:

## Use of AI Tools