Shift elasticsearch retention to 10 days.

We were keeping 14 days of elasticsearch indexes. Unfortunately we are
running out of available disk space on our elasticsearch nodes and do
not have quota to add more volumes to increase available disk. Shift to
10 days of retention while we sort out how to get more disk.

Change-Id: I011d4f16f9a74e2eb7665ef66d2193e5fda476b7
Merge "Shift elasticsearch retention to 10 days."