Fixed flaky tests and added more DcTracker tests.

Added more DcTracker tests to test different scenarios
that data should be brought up or not. This is preliminary
work for isDataAllowed refactoring needed for b/33847610

bug: 29579544, 33847610
Test: Telephony unit tests
Merged-In: I098de4de94c321d62c8724143f7d009071f472d2
Change-Id: I098de4de94c321d62c8724143f7d009071f472d2