tests: enable gating based on set of fedora tests

Tests were executed many times on AWS in testing-farm so the set
is very stable and we should be able to gate with the set.
We added nm-cloud-setup tests, few simwifi, gsm, loopback, and ovs
tests so pretty everything is covered. We can add more but that
needs to be discussed in NMCI area in mapper.yaml where gating
tests are specified.

https://src.fedoraproject.org/rpms/NetworkManager/pull-request/17

gating.yaml

@@ -0,0 +1,14 @@
+--- !Policy
+product_versions:
+  - fedora-*
+decision_context: bodhi_update_push_testing
+subject_type: koji_build
+rules:
+  - !PassingTestCaseRule {test_case_name: fedora-ci.koji-build.tier0.functional}
+--- !Policy
+product_versions:
+  - fedora-*
+decision_context: bodhi_update_push_stable
+subject_type: koji_build
+rules:
+  - !PassingTestCaseRule {test_case_name: fedora-ci.koji-build.tier0.functional}