Update listVirtualMachines API documentation with 'projectid=-1' to list all VMs in projects. (#4276)

* Enhance API list commands documentation for "listAll" and "projectid" parameters

Author: GabrielBrascher

api/src/main/java/org/apache/cloudstack/api/BaseListDomainResourcesCmd.java

@@ -21,7 +21,7 @@
 public abstract class BaseListDomainResourcesCmd extends BaseListCmd implements IBaseListDomainResourcesCmd {
 
     @Parameter(name = ApiConstants.LIST_ALL, type = CommandType.BOOLEAN, description = "If set to false, "
-        + "list only resources belonging to the command's caller; if set to true - list resources that the caller is authorized to see. Default value is false")
+        + "list only resources belonging to the command's caller; if set to true - list resources that the caller is authorized to see. Default value is false. Resources dedicated to a project are listed only if using the projectid parameter.")
     private Boolean listAll;
 
     @Parameter(name = ApiConstants.DOMAIN_ID,

api/src/main/java/org/apache/cloudstack/api/BaseListProjectAndAccountResourcesCmd.java

@@ -20,7 +20,7 @@
 
 public abstract class BaseListProjectAndAccountResourcesCmd extends BaseListAccountResourcesCmd implements IBaseListProjectAndAccountResourcesCmd {
 
-    @Parameter(name = ApiConstants.PROJECT_ID, type = CommandType.UUID, entityType = ProjectResponse.class, description = "list objects by project")
+    @Parameter(name = ApiConstants.PROJECT_ID, type = CommandType.UUID, entityType = ProjectResponse.class, description = "list objects by project; if projectid=-1 lists All VMs")
     private Long projectId;
 
     @Override