Update status in objc interop tests

src/objective-c/tests/InteropTests.m

@@ -545,7 +545,7 @@ BOOL isRemoteInteropTest(NSString *host) {
                             } else {
                               // Keepalive should kick after 1s elapsed and fails the call.
                               XCTAssertNotNil(error);
-                              XCTAssertEqual(error.code, GRPC_STATUS_INTERNAL);
+                              XCTAssertEqual(error.code, GRPC_STATUS_UNAVAILABLE);
                               XCTAssertEqualObjects(
                                   error.localizedDescription, @"keepalive watchdog timeout",
                                   @"Unexpected failure that is not keepalive watchdog timeout.");