Regenerate API samples for GET /extensions

In a subsequent commit, I make a change which requires regenerating
this API sample but doing so shows up a bunch of unrelated changes.
This commit simply regenerates the API sample without any functional
changes to highlight the non-functional sample changes.

Change-Id: I5fafff90f20af17d787039568245f598e500405e
Merge "Regenerate API samples for GET /extensions"