Progress bar background layout does not show up

Question

I have seperated the background xml and the progress xml. but the background does not show up. I am trying to implement a custom circle progress bar. I want to show 2 progresses at the same time in the progress bar.

below code is the background xml

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

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id ="@android:id/background">
        <shape
                android:innerRadiusRatio="2.6"
                android:shape="ring"
                android:thicknessRatio="20.0"
                android:useLevel="true">

            <gradient
                    android:centerColor="#333399"
                    android:endColor="#333399"
                    android:startColor="#333399"
                    android:type="sweep" />
        </shape>
    </item>
</layer-list>

below code is the progress layout

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

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/secondaryProgress">
        <shape
                android:innerRadiusRatio="2.6"
                android:shape="ring"
                android:thicknessRatio="20.0"
                android:useLevel="true">

            <gradient
                    android:centerColor="#714338"
                    android:endColor="#714338"
                    android:startColor="#714338"
                    android:type="sweep" />
        </shape>
    </item>

    <item android:id="@android:id/progress">
        <rotate
                android:fromDegrees="270"
                android:pivotX="50%"
                android:pivotY="50%"
                android:toDegrees="270">

            <shape
                    android:innerRadiusRatio="2.6"
                    android:shape="ring"
                    android:thicknessRatio="20.0"
                    android:useLevel="true">

                <rotate
                        android:fromDegrees="0"
                        android:pivotX="50%"
                        android:pivotY="50%"
                        android:toDegrees="360" />

                <gradient
                        android:centerColor="#FFFFFF"
                        android:endColor="#FFFFFF"
                        android:startColor="#FFFFFF"
                        android:type="sweep" />

            </shape>
        </rotate>
    </item>
</layer-list>

this is the progress bar code in activity.xml

<ProgressBar
            android:id="@+id/sync_progress"
            style="?android:attr/progressBarStyleHorizontal"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:indeterminate="false"
            android:padding="1dp"
            android:progressDrawable="@drawable/circular_progressbar"
            android:background="@drawable/circular_progress_bg"/>