Bug: `AdkApp` Deployment via `vertexai.Client` Fails to Inherit Location

`client.agent_engines.create` does not pass the client's `location` to the `AdkApp` instance, causing deployment to use an incorrect or default region.

**Problem:**

The provided code demonstrates a conflict between the new client-based and the older global initialization methods in the Vertex AI SDK. While `vertexai.Client` is correctly instantiated with `location="us-central1"`, the `AdkApp` object is created in a way that it remains unaware of this client-scoped configuration.

When `client.agent_engines.create(agent=app, ...)` is called, the `app` object does not carry the `us-central1` location. Consequently, the deployment process falls back to a default location (or one set by a global `vertexai.init` call), leading to a regional mismatch and deployment failures. The operation should be self-contained within the client's configuration.

**Code to Reproduce:**
```python
import vertexai
import asyncio
import logging

# Configure logging
logging.basicConfig(level=logging.INFO)

# --- Problem Area ---
# 1. Client is configured for "us-central1"
project_id = "my-project"
client = vertexai.Client(project=project_id, location="us-central1")

# 2. Agent is defined independently
from google.adk.agents import Agent
root_agent = Agent(
name="root_agent",
model="gemini-2.5-flash",
instruction="You are a helpful AI assistant designed to provide accurate and useful information.",
)

# 3. AdkApp is instantiated without knowledge of the client's location.
# The global init() further complicates which configuration is used.
from vertexai.agent_engines import AdkApp
vertexai.init(project=project_id)
app = AdkApp(agent=root_agent)
# At this point, app's internal configuration does not know about "us-central1"

# 4. Deployment is called on the client, but the `app` object lacks the correct location.
# This is where the regional mismatch occurs.
remote_agent = client.agent_engines.create(
agent=app,
config={
"staging_bucket": "gs://",
"requirements": ["google-adk", "google-cloud-aiplatform"]
}
)

print("Remote agent created successfully:")
print(remote_agent)

# --- Remote Query (will fail if deployment used the wrong region) ---
async def run_remote_query():
print("\nStreaming remote query...")
async for event in remote_agent.async_stream_query(message="hi!", user_id="test"):
print(event)

asyncio.run(run_remote_query())
```

**Expected Behavior:**

The `client.agent_engines.create()` method should ensure that the `AdkApp` instance (`app`) it is deploying inherits the configuration of the `client` object, specifically the `location`. The deployment should seamlessly proceed in `us-central1` as defined in the client.

**Actual Behavior:**

The `AdkApp` object is unaware of the `client`'s location. The deployment process initiated by `client.agent_engines.create()` uses a default or globally configured location, which conflicts with the client's explicit `us-central1` setting, causing the deployment to fail.