Update keystore2 for new linter warnings

This CL updates files used in the keystore2 tests to address new linter
warnings from the 1.52.1 compiler.

Bug: 194309655
Test: m keystore2_tests
Change-Id: Ibfa7c20ddaecbe70c7e62f8a01d93bf7d6aecee0
diff --git a/keystore2/src/database.rs b/keystore2/src/database.rs
index 33c2c32..0081bb7 100644
--- a/keystore2/src/database.rs
+++ b/keystore2/src/database.rs
@@ -4966,10 +4966,7 @@
                 Ok(KeyEntryRow {
                     id: row.get(0)?,
                     key_type: row.get(1)?,
-                    domain: match row.get(2)? {
-                        Some(i) => Some(Domain(i)),
-                        None => None,
-                    },
+                    domain: row.get::<_, Option<_>>(2)?.map(Domain),
                     namespace: row.get(3)?,
                     alias: row.get(4)?,
                     state: row.get(5)?,