identity: fix access control checks in libeic.

Also add a new libeic_test binary which has a regression test for this
vulnerability.

Bug: 190757775
Test: atest libeic_test
Test: atest VtsHalIdentityTargetTest
Test: atest CtsIdentityTestCases
Change-Id: I8344655c59930d6bf1baa4e0f8d0f60e4fc9e48d
5 files changed