Fix behavior when primary fails initialization

Fix behavior when primary fails initialization: before this, the primary
would fail and the controller would attempt to start the secondary,
which hadn't been initialized yet.

This commit also adds tests to confirm primary, secondary or both
provider failure work as intended.

Bug: 176812518
Test: atest services/tests/servicestests/src/com/android/server/location/timezone/ControllerImplTest.java
Change-Id: I9d14b98f0b2ebb262f4dd8ee1ec82d944a5b57a8