message: Fixing Java build.
  It seems that Java 7 doesn't allow converting from List<<anonymous SenderVerifyingKeysProvider>> to List<SenderVerifyingKeysProvider>.
  GitOrigin-RevId:
diff: @@ -496,7 +496,7 @@ public final class PaymentMethodTokenRecipient {
  JSONObject signedKey = new JSONObject(signedKeyAsString);
  validateSignedKey(signedKey);
  final String key = signedKey.getString(PaymentMethodTokenConstants.JSON_KEY_VALUE_KEY);
  - return Collections.singletonList(
  + SenderVerifyingKeysProvider provider =
  new SenderVerifyingKeysProvider() {
  @Override
  public List<ECPublicKey> get(String protocolVersion) throws GeneralSecurityException {
  @@ -506,7 +506,8 @@ public final class PaymentMethodTokenRecipient {
  return Collections.emptyList();
  }
  }
  - });
  + };
  + return Collections.singletonList(provider);
  }
  private JSONObject validateIntermediateSigningKey(final JSONObject intermediateSigningKey)
  