Merge "Fix kotlin nullable errors in Connectivity tests" into main

tests/common/java/android/net/KeepalivePacketDataTest.kt

tests/common/java/android/net/NetworkProviderTest.kt

tests/cts/net/src/android/net/cts/CaptivePortalTest.kt

tests/cts/net/src/android/net/cts/DscpPolicyTest.kt

tests/cts/net/src/android/net/cts/EthernetManagerTest.kt

tests/cts/net/src/android/net/cts/NetworkAgentTest.kt

tests/cts/net/src/android/net/cts/NetworkInfoTest.kt

tests/cts/net/src/android/net/cts/NetworkScoreTest.kt

tests/cts/net/src/android/net/cts/NsdManagerTest.kt

tests/cts/net/src/android/net/cts/ProxyTest.kt

...et/integrationtests/ConnectivityServiceIntegrationTest.kt

...c/com/android/server/net/integrationtests/HttpResponse.kt

...et/integrationtests/NetworkStackInstrumentationService.kt

...id/server/net/integrationtests/TestNetworkStackService.kt

tests/unit/java/android/net/NetworkTemplateTest.kt

...nit/java/com/android/server/connectivity/FullScoreTest.kt

...va/com/android/server/connectivity/mdns/MdnsPacketTest.kt