Add platform-install as a subproject

Change-Id: I898b3bdd48aef56093c9ea02e5b067d57ef5fd1a
diff --git a/settings.gradle b/settings.gradle
index f68ffd1..6efd72a 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1,3 +1,4 @@
 include 'components/maas'
 include 'components/cord-onos-publisher'
 include 'components/cord-tester'
+include 'components/platform-install'