Added Jacoco Code Coverage For Sonar.

src/main/java/com/example/service/AzureAppConfigService.java

@@ -47,7 +47,7 @@ public class AzureAppConfigService {
     public String writeValueByKey(String key, String value) {
         try {
             LOGGER.info("Writing Single Value by key");
-            if(key == null || value == null)
+            if(key == null && value == null)
                 throw new Exception("Key and Value cannot be null");
             ConfigurationSetting configurationSetting = configurationClient.setConfigurationSetting(key, null, value);
             return configurationSetting.getValue();