Fix WifiSyncFeatureManager unittest reference error

WifiSyncFeatureManager unittests were failing on ASan/LSan builds.

This CL
1. Assigned GetHostWithStatus() to variable to remove duplicate call.
2. Assigned RemoteDeviceRef by value to fix reference error.
3. Re-enables WifiSyncFeatureManager unittests.

Bug: 1117619
Change-Id: I3606294648aa3be3b33f5f83442dcbc584ecb143
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2435901
Commit-Queue: Claude van der Merwe <cvandermerwe@google.com>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Jon Mann <jonmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812379}

chromeos/services/multidevice_setup/BUILD.gn

@@ -144,12 +144,7 @@ source_set("unit_tests") {
     "multidevice_setup_impl_unittest.cc",
     "multidevice_setup_service_unittest.cc",
     "privileged_host_device_setter_impl_unittest.cc",
-
-    # TODO(crbug/1117619): Unit tests fail with asan/lsan:
-    # is_asan = true
-    # is_lsan = true
-    # is_debug = false
-    #"wifi_sync_feature_manager_impl_unittest.cc",
+    "wifi_sync_feature_manager_impl_unittest.cc",
   ]
 
   deps = [

chromeos/services/multidevice_setup/wifi_sync_feature_manager_impl_unittest.cc

@@ -128,18 +128,18 @@ class MultiDeviceSetupWifiSyncFeatureManagerImplTest
   }
 
   void SetIsWifiSyncEnabled(bool enabled) {
-    const base::Optional<multidevice::RemoteDeviceRef>& host_device =
-        fake_host_status_provider_->GetHostWithStatus().host_device();
-
     delegate_->SetIsWifiSyncEnabled(enabled);
 
-    if (fake_host_status_provider_->GetHostWithStatus().host_status() !=
-        mojom::HostStatus::kHostVerified) {
+    HostStatusProvider::HostStatusWithDevice host_with_status =
+        fake_host_status_provider_->GetHostWithStatus();
+    if (host_with_status.host_status() != mojom::HostStatus::kHostVerified) {
       return;
     }
 
+    multidevice::RemoteDeviceRef host_device = *host_with_status.host_device();
+
     bool enabled_on_backend =
-        (host_device->GetSoftwareFeatureState(
+        (host_device.GetSoftwareFeatureState(
              multidevice::SoftwareFeature::kWifiSyncHost) ==
          multidevice::SoftwareFeatureState::kEnabled);
     bool pending_request_state_same_as_backend =
@@ -149,7 +149,7 @@ class MultiDeviceSetupWifiSyncFeatureManagerImplTest
       return;
     }
 
-    VerifyLatestSetWifiSyncHostNetworkRequest(*host_device, enabled);
+    VerifyLatestSetWifiSyncHostNetworkRequest(host_device, enabled);
   }
 
   void VerifyLatestSetWifiSyncHostNetworkRequest(