Fixed failed unit test cases

The unit test case testSimError starts to fail due to the
recent CL https://android-review.googlesource.com/#/c/330668/
Fixed by adding slot id validation.

Test: runtest -x SubscriptionInfoUpdaterTest.java
bug: 29579544
Change-Id: Ie3aeeae37fc923c2d6a5e381591626245bec6132