Refactored Bazel host creation to export some of the relevant utility functions. google3 needs to make some modifications to the Bazel host to enable the Ivy migration. The functionality exported here is still needed in g3, but it allows g3 code to create the Bazel host, make necessary modifications, and then provide it to the external codebase here while everything is still compatible. For external users, this is a no-op.
PR Close#34686
cb142b6df9