What is the difference between this piece of code:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="windowActionBar">false</item>
</style>
and this one:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="android:windowActionBar">false</item>
</style>
The answer is simple. windowActionBar is an attribute provided in AppCompat library, whereas android:windowActionBar is provided in Material theme.
Same applies for all of the other attributes:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>