[tool] Update build-all app creation (flutter#7955)

Minor cleanup of the script to create the build-all app, mostly for Android:
- Don't override the minSdk to 21, since the Flutter-provided value is now 21 already.
- Don't enable multidex, since that isn't necessary for minSdk 20+.
- Remove camera_android_camerax from the direct dependency list, not camera_android, now that the endorsement has switched. This will return us to the previous, intended behavior of testing that both versions build together.
- If for some reason the Dart SDK isn't detected, use 3.0.0+ instead of 2.12.0+.

Author: stuartmorgan-g

script/tool/lib/src/create_all_packages_app_command.dart

@@ -245,19 +245,9 @@ dependencies {}
         if (gradleFileIsKotlin)
           'compileSdk': <String>['compileSdk = 34']
         else ...<String, List<String>>{
-          // minSdkVersion 21 is required by camera_android.
-          'minSdkVersion': <String>['minSdkVersion 21'],
           'compileSdkVersion': <String>['compileSdk 34'],
         }
       },
-      additions: <String, List<String>>{
-        'defaultConfig {': <String>[
-          if (gradleFileIsKotlin)
-            '        multiDexEnabled = true'
-          else
-            '        multiDexEnabled true'
-        ],
-      },
       regexReplacements: <RegExp, List<String>>{
         // Tests for https://github.com/flutter/flutter/issues/43383
         // Handling of 'dependencies' is more complex since it hasn't been very
@@ -289,7 +279,7 @@ dependencies {}
     final VersionConstraint dartSdkConstraint =
         originalPubspec.environment?[dartSdkKey] ??
             VersionConstraint.compatibleWith(
-              Version.parse('2.12.0'),
+              Version.parse('3.0.0'),
             );
 
     final Map<String, PathDependency> pluginDeps =
@@ -313,15 +303,15 @@ dependencies {}
     // An application cannot depend directly on multiple federated
     // implementations of the same plugin for the same platform, which means the
     // app cannot directly depend on both camera_android and
-    // camera_android_androidx. Since camera_android is endorsed, it will be
-    // included transitively already, so exclude it from the direct dependency
-    // list to allow including camera_android_androidx to ensure that they don't
-    // conflict at build time (if they did, it would be impossible to use
-    // camera_android_androidx while camera_android is endorsed).
+    // camera_android_androidx. Since camera_android_androidx is endorsed, it
+    // will be included transitively already, so exclude it from the direct
+    // dependency list to allow including camera_android to ensure that they
+    // don't conflict at build time (if they did, it would be impossible to use
+    // camera_android while camera_android_androidx is endorsed).
     // This is special-cased here, rather than being done via the normal
     // exclusion config file mechanism, because it still needs to be in the
     // depenedency overrides list to ensure that the version from path is used.
-    pubspec.dependencies.remove('camera_android');
+    pubspec.dependencies.remove('camera_android_camerax');
 
     app.pubspecFile.writeAsStringSync(_pubspecToString(pubspec));
   }

script/tool/test/create_all_packages_app_command_test.dart

@@ -222,7 +222,7 @@ project 'Runner', {
     });
 
     test(
-        'pubspec special-cases camera_android to remove it from deps but not overrides',
+        'pubspec special-cases camera_android_camerax to remove it from deps but not overrides',
         () async {
       writeFakeFlutterCreateOutput(testRoot);
       final Directory cameraDir = packagesDir.childDirectory('camera');
@@ -241,16 +241,16 @@ project 'Runner', {
       expect(cameraDependency, isA<PathDependency>());
       expect((cameraDependency! as PathDependency).path,
           endsWith('/packages/camera/camera'));
-      expect(cameraCameraXDependency, isA<PathDependency>());
-      expect((cameraCameraXDependency! as PathDependency).path,
-          endsWith('/packages/camera/camera_android_camerax'));
-      expect(cameraAndroidDependency, null);
-
-      final Dependency? cameraAndroidOverride =
-          pubspec.dependencyOverrides['camera_android'];
-      expect(cameraAndroidOverride, isA<PathDependency>());
-      expect((cameraAndroidOverride! as PathDependency).path,
+      expect(cameraAndroidDependency, isA<PathDependency>());
+      expect((cameraAndroidDependency! as PathDependency).path,
           endsWith('/packages/camera/camera_android'));
+      expect(cameraCameraXDependency, null);
+
+      final Dependency? cameraCameraXOverride =
+          pubspec.dependencyOverrides['camera_android_camerax'];
+      expect(cameraCameraXOverride, isA<PathDependency>());
+      expect((cameraCameraXOverride! as PathDependency).path,
+          endsWith('/packages/camera/camera_android_camerax'));
     });
 
     test('legacy files are copied when requested', () async {
@@ -342,7 +342,6 @@ android {
           buildGradle,
           containsAll(<Matcher>[
             contains('This is the legacy file'),
-            contains('minSdkVersion 21'),
             contains('compileSdk 34'),
           ]));
     });
@@ -376,9 +375,7 @@ android {
       expect(
           buildGradle,
           containsAll(<Matcher>[
-            contains('minSdkVersion 21'),
             contains('compileSdk 34'),
-            contains('multiDexEnabled true'),
             contains('androidx.lifecycle:lifecycle-runtime'),
           ]));
     });