Style in xml not working on API<21

[borjaruiz]

I have this style for my toolbar:

<style name="ToolbarTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
        <item name="fontPath">@string/font_bold</item>
        <item name="android:textColorPrimary">@color/text1</item>
        <item name="android:textColorSecondary">@color/text1</item>
        <item name="android:background">@color/toolbar_back</item>
        <item name="android:textSize">20sp</item>
    </style>

The toolbar title is showing correctly in bold typeface on API>=21 but not in older versions

What am I doing wrong?

Thanks in advance