app/src/main/res/anim/smooth_rotation.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<rotate
android:duration="1500"
android:fromDegrees="-5"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="5"
android:repeatCount="infinite"
android:repeatMode="reverse"
android:interpolator="@android:interpolator/linear" />
</set>