extract_utils: Introduce variable INITIAL_COPYRIGHT_YEAR

Let a device specify INITIAL_COPYRIGHT_YEAR=XXXX in setup-makefiles.sh
so that the correct copyright(s) is/are included in vendor makefiles.
The CyanogenMod copyright is retained when INITIAL_COPYRIGHT_YEAR<2017
and the LineageOS copyright is now included for >=2017.

Change-Id: I6895b5b69bc7ba399042ac3c29e17f3209d15f1b
1 file changed