No public methods to change the predefined margins for icons.

About font size, there is a discussion from https://github.com/aurelhubert/ahbottomnavigation/issues/64

> For now, no. The library was created to follow the guidelines (and so the text sizes) of Material Design. It could be a bit complicated to manage text sizes because there is a small increase of the text size for the selected item (so if we add a method to set the text size, we should think about the difference between selected/unselected item).

However, I checked the latest guideline: https://material.io/design/components/bottom-navigation.html#theming. I think the font size should be **12 sp** no matter the status is active or inactive, shouldn't it?

I knew there is a method to set text size by `bottomNavigation.setTitleTextSize()`, but there is no
public method to change `bottom_navigation_margin_top_active` and `bottom_navigation_margin_top_inactive` defined in dimens.xml. That caused a problem the icons moved when switching between active and inactive. I hope it can be fixed in the same position between states.

Start by locating dimens.xml and the existing bottomNavigation.setTitleTextSize() implementation. Trace how bottom_navigation_margin_top_active and bottom_navigation_margin_top_inactive are applied during active and inactive states, then verify that public setters can change them and that icon positioning remains consistent between states.

Written by the indexing model from the issue text.