Include various database PRAGMA values in dump

Sample output on Cuttlefish:

Database configuration:
  auto_vacuum = 1
  journal_mode = delete
  journal_size_limit = 1048576
  synchronous = 2
  schema_version = 15
  user_version = 0

Test: dumpsys android.security.maintenance
Change-Id: Iad4698d754728c5f30955ad503f446958cbdeec4
diff --git a/keystore2/src/database.rs b/keystore2/src/database.rs
index 9f27b5a..66b123e 100644
--- a/keystore2/src/database.rs
+++ b/keystore2/src/database.rs
@@ -3049,4 +3049,11 @@
         let app_uids_vec: Vec<i64> = app_uids_affected_by_sid.into_iter().collect();
         Ok(app_uids_vec)
     }
+
+    /// Retrieve a database PRAGMA config value.
+    pub fn pragma<T: FromSql>(&mut self, name: &str) -> Result<T> {
+        self.conn
+            .query_row(&format!("PRAGMA persistent.{name}"), (), |row| row.get(0))
+            .context(format!("failed to read pragma {name}"))
+    }
 }