build-scripts: add a script to build all carrier variants

Change-Id: I66d183f67a19b1c30a40143a3bccf031471451ea
prebuilts: add META-INF loki variant for devices that need this

Change-Id: Ib867fcc348879927f4841cc443243313d73c71ce
build-scripts: update scripts for liki installable zip package scripts

Change-Id: Iaf16aa31da83caf2337fed096ba3ce0a33439d0f