fix: logic to suppress failed metric export during client shutdown

Otel will try to do a final export when its shutting down, however that request can be rejected by the monitoring api due to rate limits. So previously we added an option to suppress the scary log warning. Unfortunately it had a logic bug that prevented it from working. This fixes it

Change-Id: Id62af7fadc8beea41f5bfd011f7bc7c0899198ab

Author: igorbernstein2

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/internal/csm/exporter/BigtableCloudMonitoringExporter.java

@@ -194,7 +194,7 @@ public void onFailure(Throwable throwable) {
               RuntimeException asyncWrapper = new RuntimeException("export failed", throwable);
               asyncWrapper.setStackTrace(stackTrace);
 
-              if (state.get() != State.Closing || state.get() != State.Closed) {
+              if (state.get() != State.Closing && state.get() != State.Closed) {
                 // ignore the export warning when client is shutting down
                 LOGGER.log(Level.WARNING, msg, asyncWrapper);
               }