Carry DoH information in PrivateDnsConfig

Extend PrivateDnsConfig to store the DoH information retrieved from
PrivateDnsConfigParcel.

Besides, in the conversion from PrivateDnsConfigParcel to
PrivateDnsConfig, `useTls` is now inferred based on the private DNS
mode instead of the private DNS hostname. This change fixes a bug
that PrivateDnsConfig::fromParcel() cannot return a PrivateDnsConfig
(useTls=true, hostname="").

The fix requires NetworkStack AIDL v19.

Bug: 240259333
Bug: 261404136
Test: atest NetworkStackTests
Test: atest NetworkStackIntegrationTests
Change-Id: Ie959e1fbe1f05743234490b8c539b7df99caac93
1 file changed