Fix broken preference controller test

This bug was introduced with the work to change certificate installation.
The CA, User and Wi-Fi certificate preferences should always be available
which is why the negative test was failing.

Bug: 144257985
Test: atest com.android.settings.security
Change-Id: Ib4a1880c3b21fa10c77568bc053b67ce4a0bbf85
1 file changed