Add plans for internal tests

gating.yaml

@@ -3,5 +3,4 @@ product_versions:
   - rhel-8
 decision_context: osci_compose_gate
 rules:
-  - !PassingTestCaseRule {test_case_name: osci.brew-build.tier0.functional}
-  - !PassingTestCaseRule {test_case_name: baseos-ci.brew-build.tier1.functional}
+  - !PassingTestCaseRule {test_case_name: osci.brew-build.tier0.functional}

plans/internal.fmf

@@ -0,0 +1,12 @@
+summary: Private (RHEL) beakerlib tests
+enabled: false
+adjust:
+  - when: distro == rhel
+    enabled: true
+    because: private tests are accesible only within rhel pipline
+discover:
+  - name: rhel
+    how: fmf
+    url: https://pkgs.devel.redhat.com/git/tests/perl-Date-Manip
+execute:
+    how: tmt