When starting your list's Activity, set its Intent flags like so:

Intent i = new Intent(...); // Your list's Intent
i.setFlags(i.getFlags() | Intent.FLAG_ACTIVITY_NO_HISTORY); // Adds the FLAG_ACTIVITY_NO_HISTORY flag
startActivity(i);

The FLAG_ACTIVITY_NO_HISTORY flag keeps the new Activity from being added to the history stack.

When starting your list's Activity, set its Intent flags like so:

Intent i = new Intent(...); // Your list's Intent
i.setFlags(i.getFlags() | Intent.FLAG_ACTIVITY_NO_HISTORY); // Adds the FLAG_ACTIVITY_NO_HISTORY flag
startActivity(i);

The FLAG_ACTIVITY_NO_HISTORY flag keeps the new Activity from being added to the history stack.

NB: As @Sam points out, you can use i.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY); instead. There is no functional difference.