ic_tab_indicator.xml

<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"
    >
    <size
        android:width="64dp"
        android:height="4dp"/>

    <corners
        android:topLeftRadius="6dp"
        android:topRightRadius="6dp"
        />
    <solid android:color="@color/colorAccent" />

</shape>