[camera_web] Fix camera initialization failure on Firefox Android

When VideoConstraints has no constraints, return true.toJS instead of an
empty object. Firefox Android rejects getUserMedia({video: {}}) with an
AbortError, but accepts {video: true}.

This fixes the camera initialization failure in availableCameras() on
Firefox Android while maintaining compatibility with other browsers.

Fixes flutter/flutter#XXXXX

Author: romeo4934

packages/camera/camera_web/CHANGELOG.md

@@ -1,6 +1,6 @@
-## NEXT
+## 0.3.6
 
-* Updates minimum supported SDK version to Flutter 3.29/Dart 3.7.
+* Fixes camera initialization failure on Firefox Android by using `{video: true}` instead of `{video: {}}` when no video constraints are specified.
 
 ## 0.3.5
 

packages/camera/camera_web/lib/src/types/camera_options.dart

@@ -108,12 +108,16 @@ class VideoConstraints {
   // TODO(dit): package:web has a class for this. Use it instead of jsify and toJson.
   /// Convert `this` to something that can be used on the browser.
   JSAny toMediaStreamConstraints() {
-    return <String, Object>{
+    final Map<String, Object> constraints = <String, Object>{
       if (width != null) 'width': width!.toJson(),
       if (height != null) 'height': height!.toJson(),
       if (facingMode != null) 'facingMode': facingMode!.toJson(),
       if (deviceId != null) 'deviceId': <String, Object>{'exact': deviceId!},
-    }.jsify()!;
+    };
+
+    // Return true instead of empty object for better browser compatibility.
+    // Firefox Android rejects getUserMedia({video: {}}) but accepts {video: true}.
+    return constraints.isEmpty ? true.toJS : constraints.jsify()!;
   }
 
   @override

packages/camera/camera_web/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera_web
 description: A Flutter plugin for getting information about and controlling the camera on Web.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera_web
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
-version: 0.3.5
+version: 0.3.6
 
 environment:
   sdk: ^3.7.0