[android] How to set default font family for entire Android app

This is how we do it:

private static void OverrideDefaultFont(string defaultFontNameToOverride, string customFontFileNameInAssets, AssetManager assets)
{
    //Load custom Font from File                
    Typeface customFontTypeface = Typeface.CreateFromAsset(assets, customFontFileNameInAssets);

    //Get Fontface.Default Field by reflection
    Class typeFaceClass = Class.ForName("android.graphics.Typeface");
    Field defaultFontTypefaceField = typeFaceClass.GetField(defaultFontNameToOverride);

    defaultFontTypefaceField.Accessible = true;
    defaultFontTypefaceField.Set(null, customFontTypeface);
}