[Android Code] 특정 패키지 설치여부 확인

private boolean isInstalledApplication(String packageName) {
  PackageManager pm = getPackageManager();
  try {
   pm.getApplicationInfo(packageName, PackageManager.GET_META_DATA);
  } catch (NameNotFoundException e) {
   e.printStackTrace();
   return false;
  }
  return true;
 }