libpolicy: Fix unittest paths.

libpolicy unittests used the old 'chromeos/policy' location instead of
just 'policy' for their includes. This patch fixes the path according
to the new location.

Bug: 23555535
TEST=mma; FEATURES=test emeger-link libchromeos

Change-Id: I300a686b82e9bedf6c3151a4b7fa5b1c10ef41d3
1 file changed