PackageWatchdog listens for NetworkStack failures

In addition to the NetworkStack app monitoring, have PackageWatchdog
register an observer to NetworkStackClient to receive severe failure
notifications, and attempt a rollback if available.

The callback is registered in onPackagesReady(), which is called in the
boot sequence just before starting the NetworkStack.

Test: installed new networkstack, killed it twice, observe rollback
Test: unit test in change on top
Bug: 133725814
Change-Id: I2cb4200b78c2482cacc4bfe2ace1581b869be512
diff --git a/tests/PackageWatchdog/Android.bp b/tests/PackageWatchdog/Android.bp
index b079965..88d92c4 100644
--- a/tests/PackageWatchdog/Android.bp
+++ b/tests/PackageWatchdog/Android.bp
@@ -18,11 +18,18 @@
     srcs: ["src/**/*.java"],
     static_libs: [
         "junit",
+        "mockito-target-extended-minus-junit4",
         "frameworks-base-testutils",
         "androidx.test.rules",
         "services.core",
+        "services.net",
     ],
     libs: ["android.test.runner"],
+    jni_libs: [
+        // mockito-target-extended dependencies
+        "libdexmakerjvmtiagent",
+        "libstaticjvmtiagent",
+    ],
     platform_apis: true,
     test_suites: ["device-tests"],
 }