[clang] [clang-format] Allow one indent level before explicit access labels (PR #227704)

[Björn Schäpers via cfe-commits]

https://github.com/HazardyKnusperkeks requested changes to this pull request.

I would convert `IndentAccessModifiers` to an enum, there's no need for an additional option.

https://github.com/llvm/llvm-project/pull/227704