There are two possible ways where you can change the icon of the HOME button in the actionbar in an Android app.
One is within the AndroidManifest.xml file itself.
However, the problem with this approach is that the same drawable will be used as launcher icons of your app.
If you want the launcher icon intact and only change the icon of the HOME button itself, you can do it by calling the setLogo() method of ActionBar.
You also need to call setDisplayUseLogoEnabled() and set it to true so the logo will be used as the HOME button’s icon.