Enable private field promotion for other packages (#134475)

New feature in upcoming Dart 3.2. See https://github.com/dart-lang/language/issues/2020. Feature is enabled by bumping the min SDK version to 3.2.

Part of https://github.com/flutter/flutter/issues/134476.

packages/flutter_driver/pubspec.yaml

@@ -3,7 +3,7 @@ description: Integration and performance test API for Flutter applications
 homepage: https://flutter.dev
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   file: 6.1.4

packages/flutter_goldens/pubspec.yaml

@@ -1,7 +1,7 @@
 name: flutter_goldens
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   # To update these, use "flutter update-packages --force-upgrade".

packages/flutter_goldens_client/pubspec.yaml

@@ -1,7 +1,7 @@
 name: flutter_goldens_client
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   # To update these, use "flutter update-packages --force-upgrade".

packages/flutter_localizations/pubspec.yaml

@@ -1,7 +1,7 @@
 name: flutter_localizations
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   # To update these, use "flutter update-packages --force-upgrade".

packages/flutter_test/pubspec.yaml

@@ -1,7 +1,7 @@
 name: flutter_test
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   # To update these, use "flutter update-packages --force-upgrade".

packages/flutter_test/test/test_config/project_root/pubspec.yaml

@@ -4,6 +4,6 @@
 name: dummy
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 # PUBSPEC CHECKSUM: 0000

packages/flutter_web_plugins/pubspec.yaml

@@ -3,7 +3,7 @@ description: Library to register Flutter Web plugins
 homepage: https://flutter.dev
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   flutter:

packages/fuchsia_remote_debug_protocol/pubspec.yaml

@@ -4,7 +4,7 @@ description: Provides an API to test/debug Flutter applications on remote Fuchsi
 homepage: https://flutter.dev
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   process: 4.2.4

packages/integration_test/example/pubspec.yaml

@@ -3,7 +3,7 @@ description: Demonstrates how to use the integration_test plugin.
 publish_to: 'none'
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
   flutter: ">=1.6.7"
 
 dependencies:

packages/integration_test/integration_test_macos/pubspec.yaml

@@ -10,7 +10,7 @@ flutter:
         pluginClass: IntegrationTestPlugin
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   flutter:

packages/integration_test/lib/common.dart

@@ -107,11 +107,11 @@ class Response {
   /// Create a list of Strings from [_failureDetails].
   List<String> _failureDetailsAsString() {
     final List<String> list = <String>[];
-    if (_failureDetails == null || _failureDetails!.isEmpty) {
+    if (_failureDetails == null || _failureDetails.isEmpty) {
       return list;
     }
 
-    for (final Failure failure in _failureDetails!) {
+    for (final Failure failure in _failureDetails) {
       list.add(failure.toJson());
     }
 

packages/integration_test/pubspec.yaml

@@ -3,7 +3,7 @@ description: Runs tests that use the flutter_test API as integration tests.
 publish_to: none
 
 environment:
-  sdk: '>=3.0.0-0 <4.0.0'
+  sdk: '>=3.2.0-0 <4.0.0'
 
 dependencies:
   flutter: