refactor: migrate dart related platform-includes to inline product option syntax

missed during #13414

Author: a-hariti

platform-includes/debug-symbols/dart-plugin/dart.flutter.mdx

@@ -19,17 +19,21 @@ The Sentry Dart Plugin requires basic configuration in your `pubspec.yaml` file:
   ]}
 />
 
-```yaml {filename:pubspec.yaml} {"onboardingOptions": {"source-context": "7-8", "source-maps": "9-10"}}
+```yaml {filename:pubspec.yaml}
 sentry:
   project: ___PROJECT_SLUG___
   org: ___ORG_SLUG___
   auth_token: ___ORG_AUTH_TOKEN___
   # Disable automatic upload of debug symbols
   # upload_debug_symbols: false
+  # ___PRODUCT_OPTION_START___ source-context
   # Enable source context
   upload_source_context: true
+  # ___PRODUCT_OPTION_END___ source-context
+  # ___PRODUCT_OPTION_START___ source-maps
   # Enable source maps
   upload_source_maps: true
+  # ___PRODUCT_OPTION_END___ source-maps
 ```
 
 <OnboardingOption optionId="dsym">

platform-includes/debug-symbols/dart-plugin/dart.mdx

@@ -19,17 +19,21 @@ The Sentry Dart Plugin requires basic configuration in your `pubspec.yaml` file:
   ]}
 />
 
-```yaml {filename:pubspec.yaml} {"onboardingOptions": {"source-context": "7-8", "source-maps": "9-10"}}
+```yaml {filename:pubspec.yaml}
 sentry:
   project: ___PROJECT_SLUG___
   org: ___ORG_SLUG___
   auth_token: ___ORG_AUTH_TOKEN___
   # Disable automatic upload of debug symbols
   # upload_debug_symbols: false
+  # ___PRODUCT_OPTION_START___ source-context
   # Enable source context
   upload_source_context: true
+  # ___PRODUCT_OPTION_END___ source-context
+  # ___PRODUCT_OPTION_START___ source-maps
   # Enable source maps
   upload_source_maps: true
+  # ___PRODUCT_OPTION_END___ source-maps
 ```
 
 <OnboardingOption optionId="dsym">
@@ -82,7 +86,7 @@ If you don't obfuscate your build, the plugin won't upload debug symbols. Additi
 If you have ProGuard (`minifyEnabled`) enabled and you want to see proper native Android stacktraces, you must upload Android Proguard/R8 mapping files. You have two options:
 
 1. **Use the Sentry Android Gradle Plugin (Recommended)**
-   
+
    After installing the [Sentry Android Gradle Plugin](/platforms/android/configuration/gradle/), set `autoInstallation` to `false` in your `app/build.gradle` file:
 
    ```groovy {filename: app/build.gradle}
@@ -92,13 +96,13 @@ If you have ProGuard (`minifyEnabled`) enabled and you want to see proper native
        }
    }
    ```
-   
+
    This is necessary because Sentry Flutter already ships with a compatible Sentry Android SDK, so we need to avoid conflicts.
-   
+
    Follow the [Android Gradle Plugin guide](/platforms/android/configuration/gradle/#proguardr8--dexguard) to complete the ProGuard mapping setup.
 
 2. **Use the Sentry CLI**
-   
+
    Alternatively, you can use the [Sentry CLI](/cli/dif/#uploading-files) to manually upload mapping files.
 
 <Alert>