Revert "Remove empty newline in build.prop"

This reverts commit 96a79c6f.

Reason for revert: b/152899887
original cl leads to build.prop getting longer and longer
from 60+ to 1k+ lines and keep increasing

Exempt-From-Owner-Approval:
BUG: 152899887

Change-Id: I83ed1702009278014c77d7e7a7305756041564de