`@ConditionalOnProperty` target property with no metadata

 Several auto-configurations use a condition on a property that has no metadata. As a result, trying to use it to customize the auto-configuration lead to a warning in an IDE.

The report detected the following:
 

org.apache.camel.model.rest.springboot.RestConfigurationDefinitionAutoConfiguration [camel.rest.enabled]
org.apache.camel.spring.boot.TypeConversionConfiguration [camel.springboot.typeConversion]

For the latter, the property in @ConditionalOnProperty must use the canonical format (i.e. must be camel.springboot.type-conversion)