Enabled NotificationSettings by default, Fix spacing, use activeMemberCount for isOneToOne.

- Enabled Notification Settings by default
- Fix spacing
- Use activeMemberCount for isOneToOne

libraries/featureflag/api/src/main/kotlin/io/element/android/libraries/featureflag/api/FeatureFlags.kt

@@ -41,8 +41,7 @@ enum class FeatureFlags(
     NotificationSettings(
         key = "feature.notificationsettings",
         title = "Show notification settings",
-        // Do not forget to edit StaticFeatureFlagProvider when enabling the feature.
-        defaultValue = false,
+        defaultValue = true,
     ),
     RichTextEditor(
         key = "feature.richtexteditor",