Add the hashCode API to EuiccRulesAuthTable

A bug in Metalava (b/311690008) means that many API Lint problems are ignored.
Even though there was no hasCode API in the EuiccRulesAuthTable, there was no warning due to b/311690008.

By the way, Bug b/311690008 is currently fixed, so I'm removing warning by adding hashCode API to EuiccRulesAuthTable.

Bug: 341152843
Test: m checkapi
Change-Id: I6e5cc35e51ab1098a52cfe3be117189b1361e4fd