Make system/bpf changes trigger connectivity CTS tests in presubmit

1. The TEST_MAPPING file should be inside bpf folder to be
   triggered on any system/bpf change.
2. It should include Connectivity module to run connectivity CTS
   tests on any change.

Test: TH
Fix: 235927729
Change-Id: I00149bf8a278853efdd2fcda4bcfb56398a73687

TEST_MAPPING

@@ -0,0 +1,17 @@
+{
+  "presubmit": [
+    {
+      "name": "libbpf_load_test"
+    }
+  ],
+  "hwasan-postsubmit": [
+    {
+      "name": "libbpf_load_test"
+    }
+  ],
+  "imports": [
+    {
+      "path": "packages/modules/Connectivity"
+    }
+  ]
+}