Settings: Added a missing FR translation

Google did a bad job.
One french translation about the battery saver is missing into the official Lollipop.

Here's the fix !

Change-Id: Ie26a1993166604414eb4dff55902a80759a3a333
Revert "Revert "settings: Fix warnings""

This reverts commit 29f58c70388857cad9f928e13881de619c1c7898.

Fixed in 2b5ad1694e849353118386ae96a8b0e5e24ea0c1

Change-Id: I79c3addc7e5c1e83b8df2033f7ee497d9f5ac4eb