You are using the AppCompat
version 21+ and it is normal.
The Action Bar follows the material design guidelines and uses a Toolbar.
As you can read here:
The use of application icon plus title as a standard layout is
discouraged on API 21 devices and newer.
If you would like an application icon (but I discourage it), you can use the method setLogo()
.
Something like this:
ActionBar actionBar = getSupportActionBar();
actionBar.setLogo(R.drawable.my_logo);
actionBar.setDisplayUseLogoEnabled(true);
actionBar.setDisplayShowHomeEnabled(true);