Bump Azure.Messaging.EventGrid from 4.10.0 to 4.15.0 in /src/ApiService

Bumps [Azure.Messaging.EventGrid](https://github.com/Azure/azure-sdk-for-net) from 4.10.0 to 4.15.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-net/releases)
- [Commits](Azure/azure-sdk-for-net@Azure.Messaging.EventGrid_4.10.0...Azure.Messaging.EventGrid_4.15.0)

---
updated-dependencies:
- dependency-name: Azure.Messaging.EventGrid
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

src/ApiService/ApiService/ApiService.csproj

@@ -28,7 +28,7 @@
     <PackageReference Include="Azure.Data.Tables" Version="12.8.0" />
     <PackageReference Include="Azure.ResourceManager.Compute" Version="1.0.0-beta.8" />
     <PackageReference Include="Azure.Identity" Version="1.8.2" />
-    <PackageReference Include="Azure.Messaging.EventGrid" Version="4.10.0" />
+    <PackageReference Include="Azure.Messaging.EventGrid" Version="4.15.0" />
     <PackageReference Include="Azure.ResourceManager" Version="1.3.1" />
     <PackageReference Include="Azure.ResourceManager.Network" Version="1.0.0" />
     <PackageReference Include="Azure.ResourceManager.Resources" Version="1.3.0" />