rotate_image_backforth.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="true" android:ordering="sequentially">
    <rotate
            android:fromDegrees="0"
            android:toDegrees="30"
            android:duration="500"
            android:pivotX="50%"
            android:pivotY="50%">
    </rotate>
    <rotate
            android:startOffset="500"
            android:fromDegrees="30"
            android:toDegrees="-30"
            android:duration="1000"
            android:pivotX="50%"
            android:pivotY="50%">
    </rotate>
    <rotate
            android:startOffset="1500"
            android:fromDegrees="-30"
            android:toDegrees="0"
            android:duration="500"
            android:pivotX="50%"
            android:pivotY="50%">
    </rotate>
</set>