48100 Make subcommands return success instead of null (cla: yes, tool, waiting for tree to go green)

48101 reset state between runs of devFS tests (cla: yes, tool, waiting for tree to go green)

48102 Improve toolchain text (cla: yes, tool, waiting for tree to go green)

48104 Improve error message when a plugin sets an invalid android package (cla: yes, tool)

48131 Roll engine fa05d367add3..d35a4b300877 (4 commits) (autoroller: commit, cla: yes)

48139 Roll engine d35a4b300877..5858519139c2 (3 commits) (autoroller: commit, cla: yes)