Show mute icon when volume at zero.

<?xml version="1.0" encoding="utf-8"?>

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

    <item android:drawable="@drawable/ic_volume_media_mute" />

</selector>

                                            : R.drawable.ic_volume_media_bt;

            }

        } else if (isStreamMuted(ss)) {

            iconRes = (ss.muted && isTv()) ? R.drawable.ic_volume_media_off : row.iconMuteRes;

            iconRes = row.iconMuteRes;

        } else {

            iconRes = mShowLowMediaVolumeIcon && ss.level * 2 < (ss.levelMax + ss.levelMin)

                      ? R.drawable.ic_volume_media_low : row.iconRes;