Split mapping file into system and product parts

Both mapping files need to be included when building sepolicy at boot
time.

Bug: 119305624
Test: boot taimen
Test: "cnd" type is declared in /vendor; "dataservice_app" type is
declared in /product. This permission is preserved
"allow cnd dataservice_app:binder { transfer call };"
Change-Id: I138f34208ea05e170defd2b4ef4700ffa81f9573