EKF: reduce prediction time step from 12 to 8 sec
EKF: reduce prediction time step from 12 to 8 sec

Reduces susceptibility to incorrect estimation of acceleration bias during sustained yaw rate.
Requires an increase in RAM allocation of 837 Bytes to allow for the longer IMU and output predictor buffers that can be created.

PX4/ecl,PX4/ecl,PX4/ecl,PX4/ecl,PX4/ecl