You are running the stock Samsung firmware for Android 4.4.2 on your Samsung Galaxy S5 regional model, G900i, for KSA.
There is an update for this but only to a later version of Android 4.4.2, see below, as Lollipop, Android 5.0, has not been released for this CSC code, KSA, yet
You can download the firmware and flash it to your phone using Odin and by following the instructions and video contained in the links of #1.11 of 40 Galaxy S5 models - Dummies Guide