FINERACT-1981: Reverse Interest Refund transaction not allowed directly with 403 error

fineract-provider/src/main/java/org/apache/fineract/portfolio/loanaccount/service/LoanWritePlatformServiceJpaRepositoryImpl.java

@@ -1426,7 +1426,7 @@ public class LoanWritePlatformServiceJpaRepositoryImpl implements LoanWritePlatf
         }
 
         if (transactionToAdjust.isInterestRefund()) {
-            throw new PlatformServiceUnavailableException("error.msg.loan.transaction.update.not.allowed",
+            throw new GeneralPlatformDomainRuleException("error.msg.loan.transaction.update.not.allowed",
                     "Interest refund transaction: " + transactionId + " cannot be reversed or adjusted directly", transactionId);
         }
 

integration-tests/src/test/java/org/apache/fineract/integrationtests/LoanInterestRefundTest.java

@@ -1240,7 +1240,7 @@ public class LoanInterestRefundTest extends BaseLoanIntegrationTest {
                     () -> loanTransactionHelper.reverseLoanTransaction(loanId, interestRefundTransactionId,
                             new PostLoansLoanIdTransactionsTransactionIdRequest().dateFormat(DATETIME_PATTERN)
                                     .transactionDate("22 January 2021").transactionAmount(0.0).locale("en")));
-            assertEquals(503, exception.getResponse().code());
+            assertEquals(403, exception.getResponse().code());
             assertTrue(exception.getMessage().contains("error.msg.loan.transaction.update.not.allowed"));
 
             Optional<GetLoansLoanIdTransactions> optMerchantIssuedTransaction = loanDetails.getTransactions().stream()