This commit provides a way to control new functionality with the
feature flags:
When working on new feature or modifying existing functionality, we can
control the code paths as follows:
if (experimentFeatures.isFeatureEnabled("my-new-feature")) {
// new code path
} else {
// old code path
}
The feature can be enabled/disabled in gerrit.config in the same way as
we do for the frontend now.
Change-Id: I9e193106852a0e47f33fc77ad69800e40b4614ee
b062da398c