[Bug/Question] NDK Camera2 callbacks (onImageAvailable) not firing in standalone C++ executable (No JNI/Java)

### **Issue Description:**

#### **1. Problem Statement**

I am developing a pure C++ tool using the NDK Camera2 API (`NdkCameraManager`, `NdkCameraDevice`, `AImageReader`) without any Java or JNI glue code. The goal is to capture frames and save them to the local filesystem from the shell.

The binary initializes successfully, and `ACameraManager_openCamera` returns `ACAMERA_OK`. However, **none of the callbacks are being triggered**:

* `ACameraDevice_StateCallbacks` (e.g., `onOpened`) are not called.
* `ACameraCaptureSession_stateCallbacks` (e.g., `onReady`) are not called.
* `AImageReader_ImageCallback` (`onImageAvailable`) is never triggered.

The program enters a loop but stays idle until the timeout, with no error messages in logcat related to camera service denials.

#### **2. Minimal Code Snippet**

I am using `ALooper` to handle asynchronous callbacks as follows:

```cpp
// In main thread
ALooper* looper = ALooper_prepare(0);

camera.startCapture(1920, 1080, 10);

int64_t start_time = time(nullptr);
while (time(nullptr) - start_time < 10) {
int ident = ALooper_pollAll(1000, nullptr, nullptr, nullptr);
if (ident == ALOOPER_POLL_TIMEOUT) {
}
}

```

#### **3. What I Have Tried**

* **Root Access:** Ran the binary as root.
* **SELinux:** Set `setenforce 0` to rule out SELinux policy issues.
* **Looper:** Added `ALooper_prepare` and `ALooper_pollAll` in the main thread to ensure the event loop is running.
* **Verification:** Verified that `cmd camera list-cameras` shows the cameras are available.

#### **4. Questions**

1. Is it possible to use NDK Camera2 API in a standalone binary without a `View` or `SurfaceTexture` from the Java side?
2. Does the `shell` UID (2000) or `root` UID (0) have inherent restrictions for accessing `CameraService` via NDK even if SELinux is disabled?
3. Am I missing any specific initialization required for the `ALooper` to correctly route `CameraService` callbacks to a native process?

Start by reviewing the ALooper_prepare and ALooper_pollAll loop and the NDK Camera2 callback setup shown in the issue. Investigate whether the standalone process, shell/root identity, and missing Java surface affect callback delivery, then document the required conditions or limitations for callbacks to fire.

Written by the indexing model from the issue text.