Merge remote-tracking branch 'aosp/upstream' into master

* aosp/upstream:
  Allow primary builder to stop bootstrap early
  Move auto-generated docs to main stage
  Refactor bpdoc
  Fix import list in singleton_ctx.go

Bug: 70516282
Test: m checkbuild
Change-Id: I090ba22a3d26a6c90f3660ad441c06a1ea4a5127