add bedrock distribution code (#358)

* add bedrock distribution code

* fix linter error

* add bedrock shields support

* linter fixes

* working bedrock safety

* change to return only one violation

* remove env var reading

* refereshable boto credentials

* remove env vars

* address raghu's feedback

* fix session_ttl passing

---------

Co-authored-by: Dinesh Yeduguru <dineshyv@fb.com>

distributions/bedrock/compose.yaml

@@ -0,0 +1,15 @@
+services:
+  llamastack:
+    image: distribution-bedrock
+    volumes:
+      - ~/.llama:/root/.llama
+      - ./run.yaml:/root/llamastack-run-bedrock.yaml
+    ports:
+      - "5000:5000"
+    entrypoint: bash -c "python -m llama_stack.distribution.server.server --yaml_config /root/llamastack-run-bedrock.yaml"
+    deploy:
+      restart_policy:
+        condition: on-failure
+        delay: 3s
+        max_attempts: 5
+        window: 60s