Reserve the icon space to avoid preference padding change

If the injection icon is to be retrieved from a provider, the preset
transparent drawable is a 1x1 icon, which may cause the preference
padding change before and after the injection icon reloading.

Bug: 253471066
Test: robotest, visual
Change-Id: Ie88f69bb047a64a6a0ee30c060d8cbb8fe27b3d7