Fix misleading `getDesiredResourceTags` behavior

[diaojinggang]

cloudformation-cli-java-plugin/src/main/java/software/amazon/cloudformation/AbstractWrapper.java

Lines 536 to 549 in 75133ad

	* resource. User-defined tags
	*
	* @param request The request object contains the new set of tags to be applied
	* at a Stack level. These will be overridden with any resource-level
	* tags which are specified as a direct resource property.
	* @return a Map of Tag names to Tag values
	*/
	@VisibleForTesting
	protected Map<String, String> getDesiredResourceTags(final HandlerRequest<ResourceT, CallbackT> request) {
	Map<String, String> desiredResourceTags = new HashMap<>();
	JSONObject object;
	if (request != null && request.getRequestData() != null) {
	replaceInMap(desiredResourceTags, request.getRequestData().getStackTags());

Here we claim getDesiredResourceTags return User-defined tags. Intuitively readers would assume it's for user tags only.

However, I have noticed system tags such as aws:cloudformation:stackid is being added in the returned results while testing my CFN stack. Given we already have request.getRequestData().getSystemTags() method for system tags, please consider to either update the code comments explaining why these non User-defined tags are here, or provide another method that will only return user tags to avoid confusions.