[GenAI Prompt API] Feature Not Found Error (606) on OnePlus Pad 3

**Describe the bug**
I am experiencing a 606-FEATURE_NOT_FOUND error when running the ML Kit GenAI sample on a OnePlus Pad 3. This device is listed in the official documentation as supported for the Prompt API.

**To Reproduce**
1.Clone the mlkit repository.

2.Build and run the genai sample project on a OnePlus Pad 3.

3.Trigger a prompt request.

4.Observe the "Feature not found" error in the UI/Logs.

**Expected Behavior:**
The GenAI Prompt API should initialize and return a response, given the device is on the supported list.

**Actual Behavior:**
com.google.mlkit.genai.common.GenAiException: [ErrorCode 606. AICore failed with error type 3-PREPARATION_ERROR and error code 606-FEATURE_NOT_FOUND]

**Smartphone:**
Device: OnePlus Pad 3

OS: OxygenOS 16.0