git: openjdk/jdk-sandbox: json: Improve JAE error msgs

[duke]

Changeset: 292e5ae8
Branch: json
Author:    Justin Lu <justin.lu at oracle.com>
Date:      2025-08-13 12:17:05 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/292e5ae8261ad2a78757cc7c9881101fdb45dbc8

Improve JAE error msgs

! src/java.base/share/classes/java/util/json/JsonArray.java
! src/java.base/share/classes/java/util/json/JsonObject.java
! src/java.base/share/classes/jdk/internal/util/json/Utils.java
! test/jdk/java/util/json/TestAssertion.java