Fixed some issues found in FindBugs security analysis.

components/apimgt-extensions/org.wso2.carbon.apimgt.application.extension.api/src/main/java/org/wso2/carbon/apimgt/application/extension/api/filter/ApiPermissionFilter.java

@@ -119,7 +119,7 @@ public class ApiPermissionFilter implements Filter {
                                 .getThreadLocalCarbonContext().getTenantId());
             return userRealm.getAuthorizationManager().isUserAuthorized(username, permission, action);
         } catch (UserStoreException e) {
-            String errorMsg = String.format("Unable to authorize the user : %s", username, e);
+            String errorMsg = String.format("Unable to authorize the user : %s", username);
             log.error(errorMsg, e);
             return false;
         }

components/certificate-mgt/org.wso2.carbon.certificate.mgt.api/src/main/java/org/wso2/carbon/certificate/mgt/jaxrs/api/common/GsonMessageBodyHandler.java

@@ -83,11 +83,7 @@ public class GsonMessageBodyHandler implements MessageBodyWriter<Object>, Messag
 
         OutputStreamWriter writer = new OutputStreamWriter(entityStream, UTF_8);
         try {
-            Type jsonType = null;
+            getGson().toJson(object, type, writer);
-            if (type.equals(type)) {
-                jsonType = type;
-            }
-            getGson().toJson(object, jsonType, writer);
         } finally {
             writer.close();
         }

components/certificate-mgt/org.wso2.carbon.certificate.mgt.cert.admin.api/src/main/java/org/wso2/carbon/certificate/mgt/cert/jaxrs/api/common/GsonMessageBodyHandler.java

@@ -83,11 +83,7 @@ public class GsonMessageBodyHandler implements MessageBodyWriter<Object>, Messag
 
         OutputStreamWriter writer = new OutputStreamWriter(entityStream, UTF_8);
         try {
-            Type jsonType = null;
+            getGson().toJson(object, type, writer);
-            if (type.equals(type)) {
-                jsonType = type;
-            }
-            getGson().toJson(object, jsonType, writer);
         } finally {
             writer.close();
         }

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/common/GsonMessageBodyHandler.java

@@ -83,11 +83,7 @@ public class GsonMessageBodyHandler implements MessageBodyWriter<Object>, Messag
 
         OutputStreamWriter writer = new OutputStreamWriter(entityStream, UTF_8);
         try {
-            Type jsonType = null;
+            getGson().toJson(object, type, writer);
-            if (type.equals(type)) {
-                jsonType = type;
-            }
-            getGson().toJson(object, jsonType, writer);
         } finally {
             writer.close();
         }

components/device-mgt/org.wso2.carbon.device.mgt.common/src/main/java/org/wso2/carbon/device/mgt/common/device/details/DeviceInfo.java

@@ -370,7 +370,7 @@ public class DeviceInfo implements Serializable {
     }
 
     public Date getUpdatedTime() {
-        if(updatedTime.equals(null)){
+        if(updatedTime == null){
             updatedTime = new Date();
         }
         return updatedTime;

components/device-mgt/org.wso2.carbon.device.mgt.common/src/main/java/org/wso2/carbon/device/mgt/common/device/details/DeviceLocation.java

@@ -137,7 +137,7 @@ public class DeviceLocation implements Serializable {
     }
 
     public Date getUpdatedTime() {
-        if(updatedTime.equals(null)){
+        if(updatedTime == null ){
             updatedTime = new Date();
         }
         return updatedTime;