Refactor chassisInterfaces into chassis_utils

Some (e.g. IBM) do not use the
`xyz.openbmc_project.Inventory.Item.Board` interface for chassis
objects. To handle the use pattern easier, this refactors the Chassis
interface into one location and it is referenced from the needed places
(e.g. `getValidChassisPath()`).

Moreover, this part is repeated many times, which goes against best
practices.

Tested:
- GET Chassis related API and check they are the same as before
- Redfish Service Validator passes

Change-Id: Id4a51986262892c5dc81b1a3bc46fa5be7c0e9da
Signed-off-by: Myung Bae <myungbae@us.ibm.com>
diff --git a/redfish-core/lib/storage.hpp b/redfish-core/lib/storage.hpp
index 6fafcce..5b2d78e 100644
--- a/redfish-core/lib/storage.hpp
+++ b/redfish-core/lib/storage.hpp
@@ -18,6 +18,7 @@
 #include "query.hpp"
 #include "redfish_util.hpp"
 #include "registries/privilege_registry.hpp"
+#include "utils/chassis_utils.hpp"
 #include "utils/collection.hpp"
 #include "utils/dbus_utils.hpp"
 
@@ -816,11 +817,8 @@
     }
 
     // mapper call lambda
-    constexpr std::array<std::string_view, 2> interfaces = {
-        "xyz.openbmc_project.Inventory.Item.Board",
-        "xyz.openbmc_project.Inventory.Item.Chassis"};
     dbus::utility::getSubTree(
-        "/xyz/openbmc_project/inventory", 0, interfaces,
+        "/xyz/openbmc_project/inventory", 0, chassisInterfaces,
         std::bind_front(afterChassisDriveCollectionSubtreeGet, asyncResp,
                         chassisId));
 }
@@ -915,13 +913,10 @@
     {
         return;
     }
-    constexpr std::array<std::string_view, 2> interfaces = {
-        "xyz.openbmc_project.Inventory.Item.Board",
-        "xyz.openbmc_project.Inventory.Item.Chassis"};
 
     // mapper call chassis
     dbus::utility::getSubTree(
-        "/xyz/openbmc_project/inventory", 0, interfaces,
+        "/xyz/openbmc_project/inventory", 0, chassisInterfaces,
         [asyncResp, chassisId,
          driveName](const boost::system::error_code& ec,
                     const dbus::utility::MapperGetSubTreeResponse& subtree) {