Add SDK check for mdns test

The mDNS test should be conducted with an SDK version higher
than Android T (align with NsdManagerTest CTS, as NsdManager is
only updatable on T+). Add an SDK version precondition check to
ensure both devices are available for testing.

Bug: 343311941
Test: atest CtsConnectivityMultiDevicesTestCases
Change-Id: Id5505b5d0746515689dc1646116a16fcfb8ece64
3 files changed