[camera] set useAutoFocus to true by default (flutter#3396)

* set useAutoFocus to true by default

there's no way to set useAutoFocus to `true` and it is `false` by default so the auto focus is not working.

* Update pubspec.yaml

* Update CHANGELOG.md

Author: markfili

packages/camera/camera/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.6.4+4
+
+* Set camera auto focus enabled by default.
+
 ## 0.6.4+3
 
 * Detect if selected camera supports auto focus and act accordingly on Android. This solves a problem where front facing cameras are not capturing the picture because auto focus is not supported.

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -96,7 +96,7 @@ public class Camera {
   private PictureCaptureRequest pictureCaptureRequest;
   private CameraRegions cameraRegions;
   private int exposureOffset;
-  private boolean useAutoFocus;
+  private boolean useAutoFocus = true;
   private Range<Integer> fpsRange;
 
   public Camera(

packages/camera/camera/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera
 description: A Flutter plugin for getting information about and controlling the
   camera on Android and iOS. Supports previewing the camera feed, capturing images, capturing video,
   and streaming image buffers to dart.
-version: 0.6.4+3
+version: 0.6.4+4
 homepage: https://github.com/flutter/plugins/tree/master/packages/camera/camera
 
 dependencies: