Add the new 'settings' shell tool to the build

The tool isn't useful unless it's actually built into products.

Bug 7299066

Change-Id: I9aaf37bde73a986d871eac6fd4dea15c192110cb
diff --git a/target/product/base.mk b/target/product/base.mk
index 8427448..9d8ef3f 100644
--- a/target/product/base.mk
+++ b/target/product/base.mk
@@ -138,6 +138,7 @@
     service \
     servicemanager \
     services \
+    settings \
     surfaceflinger \
     svc \
     system_server \