Add prepareForVideoRecording empty impl

packages/camera/camera_android_camerax/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * Updates `README.md` to reflect the fact that the `camera_android_camerax` camera plugin implementation
   is the endorsed Android implementation for `camera: ^0.11.0`.
+* Adds empty implementation for `prepareVideoRecording`, which is not used for Android.
 
 ## 0.6.4
 

packages/camera/camera_android_camerax/lib/src/android_camera_camerax.dart

@@ -867,6 +867,14 @@ class AndroidCameraCameraX extends CameraPlatform {
     }
   }
 
+  /// Prepare the capture session for video recording.
+  ///
+  /// This optimization is not required for Android.
+  @override
+  Future<void> prepareForVideoRecording() {
+    return Future<void>.value();
+  }
+
   /// Configures and starts a video recording. Returns silently without doing
   /// anything if there is currently an active recording.
   ///