java/com/android/incallui/incall/impl/res/animator/incall_button_elevation.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item
    android:state_enabled="true"
    android:state_pressed="true">
    <objectAnimator
      android:duration="@android:integer/config_shortAnimTime"
      android:propertyName="translationZ"
      android:valueTo="8dp"
      android:valueType="floatType"/>

  </item>
  <item
    android:state_checked="true"
    android:state_enabled="true"
    android:state_pressed="false">
    <objectAnimator
      android:duration="@android:integer/config_shortAnimTime"
      android:propertyName="translationZ"
      android:valueTo="4dp"
      android:valueType="floatType"/>

  </item>
  <item>
    <objectAnimator
      android:duration="@android:integer/config_shortAnimTime"
      android:propertyName="translationZ"
      android:valueTo="0dp"
      android:valueType="floatType"/>
  </item>
</selector>