code: private void deleteRSAKeys() {
          try {
              KeyStore keyStore = KeyStore.getInstance(ANDROID_KEY_STORE);
              keyStore.load(null);
              keyStore.deleteEntry(KEY_ALIAS);
              Log.d(TAG, "Deleting the existing RSA key pair from the KeyStore.");
          } catch (KeyStoreException | CertificateException | IOException | NoSuchAlgorithmException e) {
              Log.e(TAG, "Failed to remove the RSA KeyEntry from the Android KeyStore.", e);
          }
      }
docs: Removes the RSA keys generated in a previous execution.
  Used when we want the next call to {@link #encrypt(byte[])} or {@link #decrypt(byte[])}
  to recreate the keys.