Wrong example for endpoint PUT Rest API method

[Agnul97]

This pr inserts a missing parameter in the example for the PUT method of endpoint's rest APis.
With the previous example, if someone tried to update an endpoint substituting parameters in the example a 500 internal server error ewas thrown and this could lead to confusion for some clients.

[codecov]

Codecov Report

Merging #3709 (1827c09) into develop (af17f02) will increase coverage by 7.62%.
The diff coverage is n/a.

❗ Current head 1827c09 differs from pull request most recent head b69d5de. Consider uploading reports for the commit b69d5de to get more accurate results

@@              Coverage Diff              @@
##             develop    #3709      +/-   ##
=============================================
+ Coverage      41.72%   49.34%   +7.62%     
- Complexity         0        8       +8     
=============================================
  Files           1822     1822              
  Lines          33800    33800              
  Branches        2664     2664              
=============================================
+ Hits           14102    16678    +2576     
+ Misses         18717    16242    -2475     
+ Partials         981      880     -101     

Impacted Files	Coverage Δ
...g/eclipse/kapua/kura/simulator/util/Documents.java	0.00% <0.00%> (-100.00%)	⬇️
...apua/service/user/internal/UserListResultImpl.java	0.00% <0.00%> (-100.00%)	⬇️
...pua/service/device/registry/event/DeviceEvent.java	0.00% <0.00%> (-100.00%)	⬇️
...ice/management/asset/internal/DeviceAssetImpl.java	0.00% <0.00%> (-100.00%)	⬇️
...ce/management/asset/internal/DeviceAssetsImpl.java	0.00% <0.00%> (-100.00%)	⬇️
...gement/asset/xml/XmlAdaptedDeviceAssetChannel.java	0.00% <0.00%> (-100.00%)	⬇️
...e/management/bundle/internal/DeviceBundleImpl.java	0.00% <0.00%> (-100.00%)	⬇️
.../management/bundle/internal/DeviceBundlesImpl.java	0.00% <0.00%> (-100.00%)	⬇️
...nt/asset/message/internal/AssetRequestMessage.java	0.00% <0.00%> (-100.00%)	⬇️
...t/asset/message/internal/AssetResponseChannel.java	0.00% <0.00%> (-100.00%)	⬇️
... and 598 more