Android : Make it appear as if only one activity has launched when implementing a EULA

I'm trying to implement a one time EULA and password creation screen in my app.

I strife to do this as clean and seamless as possible. My current implmentation involves a SharedPreference that needs to be set, when it's not, it should display the EULA and password creation screen.

/**
 * 
 * @param context
 * @return
 */
public static boolean isFirstLaunch(Context context) {
    SharedPreferences reader = context.getSharedPreferences(
            PREFERENCES, Context.MODE_PRIVATE);
    String apiKey = reader.getString(APIKEY, "");

    return apiKey == "";
}

The API key is set when the user completes accepting the EULA and has created a password. However I see the previous activity still being launched/animated. So I have been trying remove the animation on the first activity, but no luck as of yet.

In the activity:

@Override
protected void onCreate(Bundle arg0) {
    super.onCreate(arg0);

    if (InitialLoading.isFirstLaunch(this)) {
        Intent intent = new Intent(this, EndUserAgreementActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        startActivity(intent);
        //getWindow().setWindowAnimations(0);
        overridePendingTransition(0,0);
        finish();

        return;
    }

    if (InitialLoading.isPasswordLoginEnabled(this)) {



    }

    Intent intent = new Intent(this, OverviewActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_NO_HISTORY|Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NO_ANIMATION);
    startActivity(intent);
    finish();
}

Do you guys know how I can make it look as if only one activity has been launched in all scenario's:

• (DO NOT DISPLAY)lauched activity -> EULA -> Password Creation -> launched/other activity


• (DO NOT DISPLAY)lauched activity -> Authentication screen -> launched/other activity


• lauched activity

I currently still see a flicker of the previous activity when I try to launch the EULA. I have checked Whatsapp and that app does show a flicker when launching the non-EULA activity, so I wonder if this is possible.

I already have a settings screen that disables the password screen that would launch if the authentication option remains enabled, so no worries there.

Anyway, thanks for the help.