[clang-tools-extra] [clang-tidy] use upper case letters for bool conversion suffix (PR #102831)

[via cfe-commits]

Da-Viper wrote:

> There might be people who don't want uppercase suffix, so this will cause problems to them. This should be put into a configuration option instead.

Correct me if I am wrong, but the way I see it is that if a check is applied it should align with existing checks. 

take for example if the check of `avoid-magic-number` applies a fix of creating a macro instead of a const variable. 

https://github.com/llvm/llvm-project/pull/102831