message: Fix secure storage test for timestamps: ensure timestamps are increasing.
  Closes:
  Approved by: davidiw
diff: @@ -27,7 +27,7 @@ const STORAGE_TESTS: &[fn(&mut dyn Storage)] = &[
  test_get_set_non_existent,
  test_get_uncreated_key_pair,
  test_hash_value,
  - test_timestamp,
  + test_incremental_timestamp,
  test_verify_incorrect_value_types_unwrap,
  ];
  @@ -381,7 +381,7 @@ fn test_create_sign_rotate_sign(storage: &mut dyn Storage) {
  }
  /// This test verifies that timestamps increase with successive writes
  -fn test_timestamp(storage: &mut dyn Storage) {
  +fn test_incremental_timestamp(storage: &mut dyn Storage) {
  let key = "timestamp_u64";
  let value0 = 442;
  let value1 = 450;
  @@ -393,6 +393,6 @@ fn test_timestamp(storage: &mut dyn Storage) {
  storage.set(key, Value::U64(value1)).unwrap();
  let second = storage.get(key).unwrap();
  - assert!(first.value != second.value);
  - assert!(first.last_update != second.last_update);
  + assert_ne!(first.value, second.value);
  + assert!(first.last_update < second.last_update);
  }
  