Add ConnectivityCheckTargetPreparer

ConnectivityCheckTargetPreparer is a tradefed target preparer that uses
the connectivitychecker app to verify device configuration, before
running any test.

The connectivitychecker app verifies that the device has a
pre-configured wifi configuration and can connect to it (except for
virtual devices where it may create the configuration itself), and
verifies that the device has a data-enabled SIM card inserted.

Checks are skipped if the device is not wifi- or mobile data-capable,
and can be skipped for local testing by running with:

  atest X -- --test-arg \
    com.android.testutils.ConnectivityCheckTargetPreparer:disable:true

Test: atest CtsNetTestCasesLatestSdk
Change-Id: I5b6d34a6c393863af23af57ff026b15973e9e784
diff --git a/staticlibs/testutils/app/connectivitychecker/Android.bp b/staticlibs/testutils/app/connectivitychecker/Android.bp
new file mode 100644
index 0000000..55b585a
--- /dev/null
+++ b/staticlibs/testutils/app/connectivitychecker/Android.bp
@@ -0,0 +1,29 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+android_test_helper_app {
+    name: "ConnectivityChecker",
+    srcs: ["src/**/*.kt"],
+    sdk_version: "system_current",
+    // Allow running the test on any device with SDK Q+, even when built from a branch that uses
+    // an unstable SDK, by targeting a stable SDK regardless of the build SDK.
+    min_sdk_version: "29",
+    target_sdk_version: "30",
+    static_libs: [
+        "androidx.test.rules",
+        "modules-utils-build_system",
+        "net-tests-utils",
+    ],
+    host_required: ["net-tests-utils-host-common"],
+}
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