Update OTEL config to include all fields with env variables

- Added service-name, endpoint, exporter-protocol, and headers fields
- All fields use @env() syntax to reference OTEL environment variables
- Updated both example dab-config.json and README documentation

Co-authored-by: tommasodotNET <12819039+tommasodotNET@users.noreply.github.com>

Author: Copilot

examples/data-api-builder/CommunityToolkit.Aspire.Hosting.Azure.DataApiBuilder.AppHost/dab-config.json

@@ -30,7 +30,11 @@
     },
     "telemetry": {
       "open-telemetry": {
-        "enabled": true
+        "enabled": true,
+        "service-name": "@env('OTEL_SERVICE_NAME')",
+        "endpoint": "@env('OTEL_EXPORTER_OTLP_ENDPOINT')",
+        "exporter-protocol": "grpc",
+        "headers": "@env('OTEL_EXPORTER_OTLP_HEADERS')"
       }
     }
   },

src/CommunityToolkit.Aspire.Hosting.Azure.DataApiBuilder/README.md

@@ -124,7 +124,11 @@ To enable OTEL telemetry in Data API builder, add the following configuration to
   "runtime": {
     "telemetry": {
       "open-telemetry": {
-        "enabled": true
+        "enabled": true,
+        "service-name": "@env('OTEL_SERVICE_NAME')",
+        "endpoint": "@env('OTEL_EXPORTER_OTLP_ENDPOINT')",
+        "exporter-protocol": "grpc",
+        "headers": "@env('OTEL_EXPORTER_OTLP_HEADERS')"
       }
     }
   }