Add BRILLO_USE_SHILL := 1.

Bug: 30746265
Test: mma in update_engine

Change-Id: I541824b9958670862e7e72b08901db1f6f9485c3
diff --git a/brillo_base.mk b/brillo_base.mk
index 1699423..3455c51 100644
--- a/brillo_base.mk
+++ b/brillo_base.mk
@@ -50,6 +50,7 @@
 BRILLO_USE_BINDER := 1
 BRILLO_USE_DBUS := 1
 BRILLO_USE_OMAHA := 1
+BRILLO_USE_SHILL := 1
 BRILLO_USE_WEAVE := 1
 
 # Java is not used or required for Brillo.