Enable diff stats in the git panel by default (#51215)

Joseph T. Lyons created 

Closes #ISSUE

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [X] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Enabled `diff_stats` in the git panel by default.

Change summary

assets/settings/default.json                    | 4 ++--
crates/settings_content/src/settings_content.rs | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

Detailed changes

assets/settings/default.json 🔗 

@@ -920,8 +920,8 @@
     },
     // Whether to show the addition/deletion change count next to each file in the Git panel.
     //
-    // Default: false
-    "diff_stats": false,
+    // Default: true
+    "diff_stats": true,
   },
   "message_editor": {
     // Whether to automatically replace emoji shortcodes with emoji characters.

crates/settings_content/src/settings_content.rs 🔗 

@@ -622,7 +622,7 @@ pub struct GitPanelSettingsContent {
 
     /// Whether to show the addition/deletion change count next to each file in the Git panel.
     ///
-    /// Default: false
+    /// Default: true
     pub diff_stats: Option<bool>,
 }