Return current testable networks directly in instant mode

Some MultinetworkApiTest tests require a testable network and
attempt to request cell or Wi-Fi connections. This involves
calling ConnectivityManager#requestNetwork, which requires the
CHANGE_NETWORK_STATE permission. Since instant apps cannot be
granted this permission, return currently available testable
networks directly in instant mode instead of attempting to
request new ones.

Fix: 335103621
Test: atest CtsNetTestCases:android.net.cts.MultinetworkApiTest \
      --instant
Change-Id: I51dbd33e0dab12856e1c0f387e45e6286feefe20
1 file changed