This update weighs 74.34MB which brings the latest security patches to Android. Although, there’s currently no information on exactly what other changes (if any) are included in the update. Till now there is also not any news related to Galaxy S7 security patch in UK.
Moreover, Google is rolling out mid-month security patch to the nexus devices in US to address the problem of Linux kernel emerged after the march security update. Anyhow Galaxy S7 and S7 edge doesn’t require this as both these devices runs on the newer version of the Kernel.