The legacy HTTP package was deprecated in v5 with the launch of @angular/common/http. The legacy package hasn't been published since v7, and will therefore not include a migration. PR Close #27038
How to serve the examples
All playground examples are built and served with Bazel. Below is an example that demonstrates how a specific example can be built and served with Bazel:
# e.g. src/zippy_component
yarn bazel run modules/playground/src/zippy_component:devserver
# e.g. src/upgrade
yarn bazel run modules/playground/src/upgrade:devserver