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/drivers/flowspec/BUILD b/drivers/flowspec/BUILD
index fd1b1a7..4460a0c 100644
--- a/drivers/flowspec/BUILD
+++ b/drivers/flowspec/BUILD
@@ -14,7 +14,10 @@
     app_name = "org.onosproject.drivers.flowspec",
     category = "Drivers",
     description = "Adds support for devices using flow specs.",
-    required_apps = ["org.onosproject.drivers"],
+    required_apps = [
+        "org.onosproject.drivers",
+        "org.onosproject.flowspec-api",
+    ],
     title = "Generic Flow Spec Drivers",
     url = "http://onosproject.org",
 )
diff --git a/drivers/stratum/BUILD b/drivers/stratum/BUILD
index 41db9f1..c075491 100644
--- a/drivers/stratum/BUILD
+++ b/drivers/stratum/BUILD
@@ -19,6 +19,7 @@
         "org.onosproject.generaldeviceprovider",
         "org.onosproject.drivers.gnmi",
         "org.onosproject.drivers.p4runtime",
+        "org.onosproject.pipelines.basic",
     ],
     title = "Stratum Drivers",
     url = "http://onosproject.org",