Support untrusted CNB builders when building images #41352
Description
Cloud Native Buildpacks has the concept of trusted and untrusted builders. Spring Boot only uses the creator lifecycle phase, and so considers all builders trusted. Spring Boot should allow users to configure a boolean value in the build configuration to specify whether the builder should be trusted.
The value should default to true when the default builder is used, and to false if the builder is specified in the build configuration.