Enable the Task Recommendations experiment v1

... on enwiki, dewiki, eswiki, fawiki, frwiki, hewiki, itwiki, nlwiki,
ruwiki, svwiki, ukwiki, and zhwiki.

Set two week bucketing duration.

Change-Id: Ib81746e66a9c55889947967ab1a411273e75247c
Merge "Enable the Task Recommendations experiment v1"