Add USE_FILESLIST_GO to switch to fileslist.go

fileslist.go is still disabled by default.  To enable, use:
USE_FILESLIST_GO=true m -j

Bug: 36274890
Test: Manual, with m -j

Change-Id: I722e17fa7fb6ba91e2b2c44cd7524d974cbe4a56
(cherry picked from commit 9fe97e231b7d7954a16647ea72d01d750265dc8b)
3 files changed