Reduce DnsResolverTest flaky rate

Adjust some timeout value and correct the conditional checking
for private DNS waiting mechanism.

Also move the fail() statement from callback thread to test thread.
It is used to avoid the test process crashing.

Bug: 148471807
Test: atest DnsResolverTest
Change-Id: I244cefeae97fe99838d1c72d867c1d7a1a7d5e87
3 files changed
tree: 51a4c79d9820f618c650ac45fa3e5711b008a550
  1. tests/