Adding test to create BACKEND_BUSY error

Creates multiple child procs and creates opearations in it and
parent proc waits for all child procs operations status, expects
one or more opearations to fail with backeend busy error.

Bug: 194359114
Test: atest keystore2_client_test
Change-Id: I52f95a7cfd031d80c88bfc2ca478a26572f40150
diff --git a/keystore2/test_utils/authorizations.rs b/keystore2/test_utils/authorizations.rs
index 4fbe124..d5a7b7b 100644
--- a/keystore2/test_utils/authorizations.rs
+++ b/keystore2/test_utils/authorizations.rs
@@ -22,6 +22,7 @@
 };
 
 /// Helper struct to create set of Authorizations.
+#[derive(Debug, Clone, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct AuthSetBuilder(Vec<KeyParameter>);
 
 impl Default for AuthSetBuilder {
@@ -77,6 +78,15 @@
         });
         self
     }
+
+    /// Add No_auth_required.
+    pub fn no_auth_required(mut self) -> Self {
+        self.0.push(KeyParameter {
+            tag: Tag::NO_AUTH_REQUIRED,
+            value: KeyParameterValue::BoolValue(true),
+        });
+        self
+    }
 }
 
 impl Deref for AuthSetBuilder {