Incorrect Javadoc for methods in HeadersConfigurer

### Summary

The Javadoc for some methods, including `xssProtection()`, `cacheControl()`, `httpStrictTransportSecurity()`, has an incorrect return type.

### Actual Behavior

The return type is listed as `HeadersConfigurer`

### Expected Behavior

The return type should be the matching configurer for each method.
`XXssConfig` for `xssProtection()`
`CacheControlConfig` for `cacheControl()`
etc
