Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 6.3.3
• Cross-platform modules: 6.2.3
• Android Runtime: 6.2.0
• Plugin(s):

Describe the bug
There is a difference between multiple devices in font icon size (in actionbar). As following:

To Reproduce

<ActionBar class="saz-action-bar">
    <NavigationButton icon="font://&#xf013;" class="fa actionbar-setting" ios:visibility="collapsed"></NavigationButton>
</ActionBar>

Expected behavior
To have a same icon size.