外圍寵物

usage: fx set-petal none|fuchsia

"none" configures jiri to fetch all repos at the global integration version,
and is the recommended default.

Other values configure jiri to fetch that specific petal's repo at
top-of-tree (HEAD) instead of the globally integration version. This means a
"jiri update" will pull down committed but not yet integrated changes, which
will be faster but may be less stable.