Added the functionality to allow the disabled and defaults-disabled
attribute of <header> tag to accept a placeholder and resolve it during
parsing.
- Updated the spring-security .rnc files starting from 4.2 up to 5.2
with xsd:token type instead of boolean
- Added unit tests for headers.disabled and headers.defaults-disabled
attributes with placeholder
- Modified the HeadersBeanDefinitionParser to support resolving
placeholders
- Updated spring.schemas to point to latest spring-security-5.2.xsd
Fixes gh-6547
3617fd257e