Split CommonGlobalSystemIncludes out of CommonGlobalIncludes in
preparation for moving global includes from -isystem to -I.
Bug: 31492149
Change-Id: Ib935ea038cdbf9515dc2ab68d7fff924c370906a
Bug: http://b/30421084
Change-Id: I8b65669ef9f60f85202295de117d3806d3a5b1f6
Test: Tested build, boot and common usage for several devices in AOSP
and internal branch.