Fixes for problems with starting and stopping apps in a minimal system

- Missing app dependencies
- Incorrect provider registrations
- Fatal execeptions thrown when external resources are not present

Change-Id: I3fdcf0666c88a47f399a722a9ab549d1104ff40e
diff --git a/apps/l3vpn/BUILD b/apps/l3vpn/BUILD
index 1c4b585..8e670a4 100644
--- a/apps/l3vpn/BUILD
+++ b/apps/l3vpn/BUILD
@@ -24,6 +24,8 @@
     "org.onosproject.models.common",
     "org.onosproject.models.l3vpn",
     "org.onosproject.bgpcep",
+    "org.onosproject.pcep",
+    "org.onosproject.bgp",
 ]
 
 osgi_jar_with_tests(