libbinder_ndk: convenience method for okay status

Before:
 return ScopedAStatus(AStatus_newOk());

After:
 return ScopedAStatus::ok();

Bug: 111445392
Test: atest android.binder.cts (using this)
Change-Id: Id45528c101ff3a965d7c84ff5946e48179bf9285
diff --git a/libs/binder/ndk/include_ndk/android/binder_auto_utils.h b/libs/binder/ndk/include_ndk/android/binder_auto_utils.h
index 5c26039..e2c0cfa 100644
--- a/libs/binder/ndk/include_ndk/android/binder_auto_utils.h
+++ b/libs/binder/ndk/include_ndk/android/binder_auto_utils.h
@@ -198,6 +198,11 @@
      * See AStatus_isOk.
      */
     bool isOk() { return get() != nullptr && AStatus_isOk(get()); }
+
+    /**
+     * Convenience method for okay status.
+     */
+    static ScopedAStatus ok() { return ScopedAStatus(AStatus_newOk()); }
 };
 
 /**