Replace rule/expected_error_code with non-deprecated versions

This patch set replaces deprecated occurrences of rule with
rules and expected_error_code with expected_error_codes in
rbac_rule_validation.action decorator.

Along with removing the parameters from the decorator, all the
API tests have been changed to use the non-deprecated parameters
instead. Unit tests have also been updated.

Change-Id: I6485b6c57795b5fe75e2b339d5c9720da30be564
diff --git a/releasenotes/notes/remove-deprecated-rules-expected-error-codes-params-52071a83113934fd.yaml b/releasenotes/notes/remove-deprecated-rules-expected-error-codes-params-52071a83113934fd.yaml
new file mode 100644
index 0000000..16b2e03
--- /dev/null
+++ b/releasenotes/notes/remove-deprecated-rules-expected-error-codes-params-52071a83113934fd.yaml
@@ -0,0 +1,13 @@
+---
+upgrade:
+  - |
+    The following deprecated parameters in ``rbac_rule_validation.action``
+    decorator:
+
+    * ``rule``
+    * ``expected_error_code``
+
+    have been removed. Use the non-deprecated versions instead:
+
+    * ``rules``
+    * ``expected_error_codes``