[clang-format] `AlignAfterOpenBracket: BlockIndent` fails if bracket starts before `ContinuationIndentWidth`

This is most easily seen on functions with `AlwaysBreakAfterReturnType` enabled or on constructors with short class names.

Given this config:
```yaml
AlignAfterOpenBracket: BlockIndent
AlwaysBreakAfterReturnType: TopLevel
```

This formats as expected:
```cpp
void
LogE(
std::string_view message,
std::source_location loc = std::source_location::current()
) {
std::println(std::cerr, "{}({}): {}", loc.file_name(), loc.line(), message);
}
```

With one less character in the function name, it formats like this:
```cpp
void
Log(std::string_view message,
std::source_location loc = std::source_location::current()) {
std::println(std::cerr, "{}({}): {}", loc.file_name(), loc.line(), message);
}
```

It seemingly falls back to using `AlignAfterOpenBracket: DontAlign` if the opening bracket starts before the value of `ContinuationIndentWidth` (`4` by default).

*Tested with version `18.1.3 (Ubuntu)` and `22.0.0git (commit 3c39187)`*

Start by reproducing the clang-format behavior with the YAML configuration and C++ examples in the issue, comparing the function names that differ by one character. Trace the formatting path for AlignAfterOpenBracket: BlockIndent and ContinuationIndentWidth, then verify that the corrected output preserves block indentation for both examples.

Written by the indexing model from the issue text.