Add E2E test for ADK demo example (#1115)

* Restructure the location of the `configs` and `data` directories to match other NAT examples.

## By Submitting this PR I confirm:
- I am familiar with the [Contributing Guidelines](https://github.com/NVIDIA/NeMo-Agent-Toolkit/blob/develop/docs/source/resources/contributing.md).
- We require that all contributors "sign-off" on their commits. This certifies that the contribution is your original work, or you have rights to submit it under the same license, or a compatible license.
  - Any contribution which contains commits that are not Signed-Off will not be accepted.
- When the PR is ready for review, new or existing tests cover these changes.
- When the PR is ready for review, the documentation is up to date with these changes.




## Summary by CodeRabbit

* **Tests**
  * Added end-to-end integration tests for the ADK demo framework.

* **Chores**
  * Added configuration and data structure support for the ADK demo example.

Authors:
  - David Gardner (https://github.com/dagardner-nv)

Approvers:
  - Will Killian (https://github.com/willkill07)

URL: #1115

Author: dagardner-nv

examples/frameworks/adk_demo/configs

@@ -0,0 +1 @@
+src/nat_adk_demo/configs

examples/frameworks/adk_demo/data

@@ -0,0 +1 @@
+src/nat_adk_demo/data

examples/frameworks/adk_demo/configs/config.yml renamed to examples/frameworks/adk_demo/src/nat_adk_demo/configs/config.yml

@@ -0,0 +1,32 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from pathlib import Path
+
+import pytest
+
+
+@pytest.mark.integration
+@pytest.mark.usefixtures("openai_api_key")
+async def test_full_workflow():
+    from nat.test.utils import locate_example_config
+    from nat.test.utils import run_workflow
+    from nat_adk_demo.agent import ADKFunctionConfig
+
+    config_file: Path = locate_example_config(ADKFunctionConfig)
+
+    await run_workflow(config_file=config_file,
+                       question="What is the weather and time in New York today?",
+                       expected_answer="weather")