Policy equality fails for binding list order

[chingor13]

The binding list order should not matter for the equivalence of Policy objects:

  @Test
  public void testPolicyOrderShouldNotMatter() {
    Role role1 = Role.of("role1");
    Identity identity1 = Identity.user("user1@example.com");
    Role role2 = Role.of("role2");
    Identity identity2 = Identity.user("user2@example.com");
    Policy policy1 = Policy.newBuilder()
            .addIdentity(role1, identity1)
            .addIdentity(role2, identity2)
            .build();
    Policy policy2 = Policy.newBuilder()
            .addIdentity(role2, identity2)
            .addIdentity(role1, identity1)
            .build();
    assertEquals(policy1, policy2);
  }

[chingor13]

In #110, we switched the data model from a Map to a List and List equality is order dependenct