Merge remote-tracking branch 'goog/mirror-aosp-master' into rvc-dev

Update rvc-dev build/blueprint to match current AOSP master.

* goog/mirror-aosp-master:
  WalkDeps - only record module visited when it has been recursed into
  Allow missing variants when allowMissingDependencies=true
  bpmodify: fix os.Exit() shouldn't shadow panic()
  bpmodify: respect exitCode
  Set bpmodify usage function
  Fix bug in buildPropertyMap in previous commit.
  Fix missing dependencies from mutators
  Implement list of maps
  In kzip files, compilation unit paths should be relative to top.

Fixes: 150689149
Test: m checkbuild
Change-Id: I38d4b4f5fd51f9467019b7ed8cdeaec1e0798ae3