chore: fix setup_telemetry script (#3680)

# What does this PR do?
Added missing configuration files

## Test Plan
run ./scripts/telemetry/setup_telemetry.sh
```
OTEL_SERVICE_NAME=llama_stack OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318 TELEMETRY_SINKS=otel_trace,otel_metric uv run --with llama-stack llama stack build --distro=starter --image-type=venv --run
```
Navigate to grafana localhost:3000, query metrics and traces

scripts/telemetry/otel-collector-config.yaml

@@ -0,0 +1,40 @@
+receivers:
+  otlp:
+    protocols:
+      grpc:
+        endpoint: 0.0.0.0:4317
+      http:
+        endpoint: 0.0.0.0:4318
+
+processors:
+  batch:
+    timeout: 1s
+    send_batch_size: 1024
+
+exporters:
+  # Export traces to Jaeger
+  otlp/jaeger:
+    endpoint: jaeger:4317
+    tls:
+      insecure: true
+
+  # Export metrics to Prometheus
+  prometheus:
+    endpoint: 0.0.0.0:9464
+    namespace: llama_stack
+
+  # Debug exporter for troubleshooting
+  debug:
+    verbosity: detailed
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [otlp/jaeger, debug]
+
+    metrics:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [prometheus, debug]