Support BuildProperties bean in Spring Boot by writing META-INF/build-info.properties

[plaird]

The BuildProperties bean in Spring Boot is loaded from data populated in META-INF/build-info.properties

• https://docs.spring.io/spring-boot/docs/current/maven-plugin/reference/htmlsingle/#goals-build-info
• https://golb.hplar.ch/2019/06/expose-build-information.html#spring-boot
• https://www.vojtechruzicka.com/spring-boot-version/
• https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/info/BuildProperties.html

It allows for custom properties to be added. We should support that too.

[plaird]

I don't see the value in this. The git.properties data for us has been helpful, but we have never wanted the data that comes from build.properties (maven gav).

If you have a real use case where build-info.properties provides value, where git.properties can't, let me know. Otherwise this will remain unworked.

[plaird]

There is a reference to a use case involving build-info.properties here #205 , but not clear how important the file is.

[plaird]

Coincidentally, we found a use case internally. A team wants CI build data published into BuildProperties. We found that there was nothing general purpose to bake into rules_spring, but we can provide an example.

[plaird]

The example has been added to demoapp as #258