Android button theme with selector

selector_button.xml

<selector
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:exitFadeDuration="100">

    <item android:state_pressed="true">
        <shape android:shape="oval">
            <solid android:color="?attr/colorPrimaryAlpha" />
        </shape>
    </item>
  
    <item android:state_focused="true">
        <shape android:shape="oval">
            <solid android:color="?attr/colorPrimaryAlpha" />
        </shape>
    </item>

    <item>
        <shape android:shape="oval">
            <solid android:color="?attr/colorPrimary" />
        </shape>
    </item>

</selector>