fix: Multi-button service mapping improvements.

For multi-button devices, we were waiting to populate the mappings to
associate the multiple button service resources to the single device
record from the API responses we perform during the `init` handler.

This could lead to inconsistent state or failure to maintain mappings in
situations where those API calls failed for any reason.

We still need to make those API calls during `init` to establish the
current state of the device, but we now populate the mappings from
cached data (if it exists) instead of relying on those initial API calls
to resolve properly.

Author: dljsjr

drivers/SmartThings/philips-hue/src/handlers/lifecycle_handlers/button.lua

@@ -119,6 +119,25 @@ function ButtonLifecycleHandlers.init(driver, device)
   if not hue_id_to_device[device_button_resource_id] then
     hue_id_to_device[device_button_resource_id] = device
   end
+
+  local maybe_idx_map = device:get_field(Fields.BUTTON_INDEX_MAP)
+  local svc_rids_for_device = driver.services_for_device_rid[hue_device_id] or {}
+
+  if not svc_rids_for_device[device_button_resource_id] then
+    svc_rids_for_device[device_button_resource_id] = HueDeviceTypes.BUTTON
+  end
+
+  for resource_id, _ in pairs(maybe_idx_map or {}) do
+    if not hue_id_to_device[resource_id] then
+      hue_id_to_device[resource_id] = device
+    end
+
+    if not svc_rids_for_device[resource_id] then
+      svc_rids_for_device[resource_id] = HueDeviceTypes.BUTTON
+    end
+  end
+  driver.services_for_device_rid[hue_device_id] = svc_rids_for_device
+
   local button_info, err
   button_info = Discovery.device_state_disco_cache[device_button_resource_id]
   if not button_info then