Allow own app installation

I need to update my apk frequently and hence i check version on device and then download the new apk from server and update my app from within the app. 

i used standard sdk so as to stop other apps from being installed on device but my problem is i aint able to updare my own app

Though i used the following code to add my package name to whitelist

     applicationPolicy.addAppPackageNameToWhiteList("com.x.y")

i use following code to stop other app install

    restrictionPolicy.setAllowNonMarketApps(false);
    restrictionPolicy.setNonTrustedAppInstallBlock(true);

How can i allow my app to install latest apk keepin other app install blocked.