It’s much easier to just check your current app version.
PackageInfo packageInfo = activity.getPackageManager()
.getPackageInfo(activity.getPackageName(), 0);
int versionCode = packageInfo.versionCode;
When your app starts, you check your SharedPreferences for an integer value with the version code. If there is none, or if it doesn’t match, display the EULA. After the user accepts the EULA, write the versionCode value to the SharedPreferences.
versionCode
will match the version number you store in the Manifest.