left_arrow.xml

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="25dp"
    android:height="25dp"
    android:viewportWidth="490.4"
    android:viewportHeight="490.4">

    <path
        android:fillColor="#000000"
        android:pathData="M245.2,490.4c135.2,0,245.2-110,245.2-245.2S380.4,0,245.2,0S0,110,0,245.2C0,380.4,110,490.4,245.2,490.4z
M245.2,24.5
c121.7,0,220.7,99,220.7,220.7s-99,220.7-220.7,220.7s-220.7-99-220.7-220.7S123.5,24.5,245.2,24.5z" />
    <path
        android:fillColor="#000000"
        android:pathData="M198.9,322.8c2.4,2.4,5.5,3.6,8.7,3.6s6.3-1.2,8.7-3.6c4.8-4.8,4.8-12.5,0-17.3l-48-48h183.4c6.8,0,12.3-5.5,12.3-12.3
s-5.5-12.3-12.3-12.3H168.3l48-48c4.8-4.8,4.8-12.5,0-17.3s-12.5-4.8-17.3,0l-68.9,68.9c-4.8,4.8-4.8,12.5,0,17.3L198.9,322.8z" />
</vector>

left_selected.xml

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="25dp"
    android:height="25dp"
    android:viewportWidth="490.4"
    android:viewportHeight="490.4">

    <path
        android:fillColor="#FF4081"
        android:pathData="M245.2,490.4c135.2,0,245.2-110,245.2-245.2S380.4,0,245.2,0S0,110,0,245.2C0,380.4,110,490.4,245.2,490.4z
M245.2,24.5
c121.7,0,220.7,99,220.7,220.7s-99,220.7-220.7,220.7s-220.7-99-220.7-220.7S123.5,24.5,245.2,24.5z" />
    <path
        android:fillColor="#FF4081"
        android:pathData="M198.9,322.8c2.4,2.4,5.5,3.6,8.7,3.6s6.3-1.2,8.7-3.6c4.8-4.8,4.8-12.5,0-17.3l-48-48h183.4c6.8,0,12.3-5.5,12.3-12.3
s-5.5-12.3-12.3-12.3H168.3l48-48c4.8-4.8,4.8-12.5,0-17.3s-12.5-4.8-17.3,0l-68.9,68.9c-4.8,4.8-4.8,12.5,0,17.3L198.9,322.8z" />
</vector>

left_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/left_selected" android:state_checked="true" />
    <item android:drawable="@drawable/left_arrow" android:state_checked="false"/>

</selector>

radioButton.xml

<RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/leftObserver"
                android:button="@null"
                android:background="@drawable/left_selector"
                android:layout_marginLeft="4dp"
                android:layout_marginRight="4dp"
                />

right_arrow.xml

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="25dp"
    android:height="25dp"
    android:viewportWidth="490.4"
    android:viewportHeight="490.4">

    <path
        android:fillColor="#000000"
        android:pathData="M245.2,490.4c135.2,0,245.2-110,245.2-245.2S380.4,0,245.2,0S0,110,0,245.2S110,490.4,245.2,490.4z
M245.2,24.5
c121.7,0,220.7,99,220.7,220.7s-99,220.7-220.7,220.7s-220.7-99-220.7-220.7S123.5,24.5,245.2,24.5z" />
    <path
        android:fillColor="#000000"
        android:pathData="M138.7,257.5h183.4l-48,48c-4.8,4.8-4.8,12.5,0,17.3c2.4,2.4,5.5,3.6,8.7,3.6s6.3-1.2,8.7-3.6l68.9-68.9
c4.8-4.8,4.8-12.5,0-17.3l-68.9-68.9c-4.8-4.8-12.5-4.8-17.3,0s-4.8,12.5,0,17.3l48,48H138.7c-6.8,0-12.3,5.5-12.3,12.3
C126.4,252.1,131.9,257.5,138.7,257.5z" />
</vector>

right_selected.xml

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="25dp"
    android:height="25dp"
    android:viewportWidth="490.4"
    android:viewportHeight="490.4">

    <path
        android:fillColor="#FF4081"
        android:pathData="M245.2,490.4c135.2,0,245.2-110,245.2-245.2S380.4,0,245.2,0S0,110,0,245.2S110,490.4,245.2,490.4z
M245.2,24.5
c121.7,0,220.7,99,220.7,220.7s-99,220.7-220.7,220.7s-220.7-99-220.7-220.7S123.5,24.5,245.2,24.5z" />
    <path
        android:fillColor="#FF4081"
        android:pathData="M138.7,257.5h183.4l-48,48c-4.8,4.8-4.8,12.5,0,17.3c2.4,2.4,5.5,3.6,8.7,3.6s6.3-1.2,8.7-3.6l68.9-68.9
c4.8-4.8,4.8-12.5,0-17.3l-68.9-68.9c-4.8-4.8-12.5-4.8-17.3,0s-4.8,12.5,0,17.3l48,48H138.7c-6.8,0-12.3,5.5-12.3,12.3
C126.4,252.1,131.9,257.5,138.7,257.5z" />
</vector>

right_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/right_selected" android:state_checked="true" />
    <item android:drawable="@drawable/right_arrow" android:state_checked="false"/>


</selector>