Camera NDK: don't explicit delete ACameraMetadata

To fix the warning in RefBase destructor.

Test: NDK CTS tests, and ARCore measure app.
Bug: 112775599
Change-Id: Ia448ac6d7e6c17699c16d287f65fc2826c9d7578
diff --git a/camera/ndk/impl/ACameraManager.cpp b/camera/ndk/impl/ACameraManager.cpp
index c59d0e7..ee67677 100644
--- a/camera/ndk/impl/ACameraManager.cpp
+++ b/camera/ndk/impl/ACameraManager.cpp
@@ -402,7 +402,7 @@
 }
 
 camera_status_t ACameraManager::getCameraCharacteristics(
-        const char *cameraIdStr, ACameraMetadata **characteristics) {
+        const char* cameraIdStr, sp<ACameraMetadata>* characteristics) {
     Mutex::Autolock _l(mLock);
 
     sp<hardware::ICameraService> cs = CameraManagerGlobal::getInstance().getCameraService();
@@ -437,18 +437,16 @@
         const char* cameraId,
         ACameraDevice_StateCallbacks* callback,
         /*out*/ACameraDevice** outDevice) {
-    ACameraMetadata* rawChars;
-    camera_status_t ret = getCameraCharacteristics(cameraId, &rawChars);
+    sp<ACameraMetadata> chars;
+    camera_status_t ret = getCameraCharacteristics(cameraId, &chars);
     Mutex::Autolock _l(mLock);
     if (ret != ACAMERA_OK) {
         ALOGE("%s: cannot get camera characteristics for camera %s. err %d",
                 __FUNCTION__, cameraId, ret);
         return ACAMERA_ERROR_INVALID_PARAMETER;
     }
-    std::unique_ptr<ACameraMetadata> chars(rawChars);
-    rawChars = nullptr;
 
-    ACameraDevice* device = new ACameraDevice(cameraId, callback, std::move(chars));
+    ACameraDevice* device = new ACameraDevice(cameraId, callback, chars);
 
     sp<hardware::ICameraService> cs = CameraManagerGlobal::getInstance().getCameraService();
     if (cs == nullptr) {