Set a default build strategy for new plan branches

With plans like https://confluence-bamboo.atlassian.com/browse/CONFFUNC-MAIN, which is our first plan to run the acceptance and unit tests, we face the problem that the branch plans created by the automatic branch creation feature inherit the polling interval of their master/template. I'd like to argue that the branch builds could do with a lower polling interval, as the development flow for them is often to ignore the build failures on an early stage of the issue development and care about them once they want to merge upstream. In order to cope with that, I'd like to be able to set or multiply the inherited polling interval for automatic branch (config/plan) creation.