make dotnet_style_require_accessibility_modifiers a warning (#1269)

Author: SimonCropp

.editorconfig

@@ -57,6 +57,9 @@ dotnet_style_coalesce_expression = true : suggestion
 dotnet_style_null_propagation = true : suggestion
 dotnet_style_explicit_tuple_names = true : suggestion
 
+# Require default accessibility modifiers to be defined
+dotnet_style_require_accessibility_modifiers=always:warning
+
 # Naming rules - async methods to be prefixed with Async
 dotnet_naming_rule.async_methods_must_end_with_async.severity = warning
 dotnet_naming_rule.async_methods_must_end_with_async.symbols = method_symbols

src/Sentry/Envelopes/Envelope.cs

@@ -72,27 +72,27 @@ public async Task SerializeAsync(Stream stream, CancellationToken cancellationTo
         public void Dispose() => Items.DisposeAll();
 
         // limited SDK information (no packages)
-        static IReadOnlyDictionary<string, string?> sdkHeader = new Dictionary<string, string?>(2, StringComparer.Ordinal)
+        private static readonly IReadOnlyDictionary<string, string?> SdkHeader = new Dictionary<string, string?>(2, StringComparer.Ordinal)
         {
             ["name"] = SdkVersion.Instance.Name,
             ["version"] = SdkVersion.Instance.Version
         };
 
-        static IReadOnlyDictionary<string, object?> defaultHeader = new Dictionary<string, object?>(1, StringComparer.Ordinal)
+        private static readonly IReadOnlyDictionary<string, object?> DefaultHeader = new Dictionary<string, object?>(1, StringComparer.Ordinal)
         {
-            ["sdk"] = sdkHeader
+            ["sdk"] = SdkHeader
         };
 
         private static IReadOnlyDictionary<string, object?> CreateHeader(SentryId? eventId = null)
         {
             if (eventId is null)
             {
-                return defaultHeader;
+                return DefaultHeader;
             }
 
             return new Dictionary<string, object?>(2, StringComparer.Ordinal)
             {
-                ["sdk"] = sdkHeader,
+                ["sdk"] = SdkHeader,
                 [EventIdKey] = eventId.Value.ToString()
             };
         }