packages/MediaComponents/res/values/style.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="TransportControlsButton">
        <item name="android:background">@null</item>
        <item name="android:layout_width">70dp</item>
        <item name="android:layout_height">40dp</item>
    </style>

    <style name="TransportControlsButton.Previous">
        <item name="android:src">@drawable/ic_skip_previous</item>
    </style>

    <style name="TransportControlsButton.Next">
        <item name="android:src">@drawable/ic_skip_next</item>
    </style>

    <style name="TransportControlsButton.Pause">
        <item name="android:src">@drawable/ic_pause_circle_filled</item>
    </style>

    <style name="TransportControlsButton.Ffwd">
        <item name="android:src">@drawable/ic_forward_30</item>
    </style>

    <style name="TransportControlsButton.Rew">
        <item name="android:src">@drawable/ic_rewind_10</item>
    </style>


    <style name="TitleBarButton">
        <item name="android:background">@null</item>
        <item name="android:layout_width">36dp</item>
        <item name="android:layout_height">36dp</item>
        <item name="android:layout_margin">10dp</item>
    </style>

    <style name="BottomBarButton">
        <item name="android:background">@null</item>
        <item name="android:layout_width">44dp</item>
        <item name="android:layout_height">34dp</item>
        <item name="android:layout_marginTop">5dp</item>
        <item name="android:layout_marginBottom">5dp</item>
        <item name="android:paddingLeft">5dp</item>
        <item name="android:paddingRight">5dp</item>
    </style>

    <style name="BottomBarButton.CC">
        <item name="android:src">@drawable/ic_media_subtitle_disabled</item>
    </style>

    <style name="BottomBarButton.FullScreen">
        <item name="android:src">@drawable/ic_fullscreen</item>
    </style>

    <style name="BottomBarButton.OverflowRight">
        <item name="android:src">@drawable/ic_chevron_right</item>
    </style>

    <style name="BottomBarButton.OverflowLeft">
        <item name="android:src">@drawable/ic_chevron_left</item>
    </style>

    <style name="BottomBarButton.Settings">
        <item name="android:src">@drawable/ic_settings</item>
    </style>

    <style name="BottomBarButton.AspectRatio">
        <item name="android:src">@drawable/ic_aspect_ratio</item>
    </style>

    <style name="BottomBarButton.Mute">
        <item name="android:src">@drawable/ic_mute</item>
    </style>

</resources>