Order details: When editing, some number input fields are missing focus indicator

[hafizrahman]

While checking out Order Details -> Edit, I found that some number input fields do not have a focus indicator (e.g: a cursor) if we tap into it. So we can write things into it, but it's hard to tell that it's focused:

1. Amount field in Add custom amount -> fixed amount:

IMG_3864.MP4

2. Amount field in In Add shipping

IMG_3865.MP4

[dangermattic]

🚫 Please add a type label (e.g. type: enhancement) and a feature label (e.g. feature: stats) to this issue.

[selanthiraiyan]

I think this is the same issue as #13956