sdk: Indicate that session_timeout is in minutes

This patch changes the SDK so that the documentation for the
"session_timeout" parameter explicitly indicates that the unit is
minutes.

Change-Id: I4d82a2e990e7286fb3a5858c6d8dbe52f8a75a78
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>
(cherry picked from commit 548a1c5901d90611c30798fdacb97f409f6a024d)