[clang-format] PR50727 C# Invoke Lamda Expression indentation incorrect

https://bugs.llvm.org/show_bug.cgi?id=50727

When processing C# Lambda expression in the indentation can goes a little wrong,
resulting the the closing } being at the wrong indentation level and meaning the remaining part of the file is
incorrectly indented.

This can be a fairly common pattern for when C# wants to peform a UI action from a thread,
and it wants to invoke that action on the main thread

Reviewed By: exv, jbcoe

Differential Revision: https://reviews.llvm.org/D104388