Create Stackdriver module and inject it into backend module

This adds Stackdriver as a DI module into the registry codebase. This is a
necessary prerequisite for using Stackdriver based monitoring. For now, I'm
only adding it to the backend module as it will be more work to add it to the
frontend module.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126730925

java/google/registry/module/backend/BackendComponent.java

@@ -27,6 +27,7 @@ import google.registry.groups.GroupsModule;
 import google.registry.groups.GroupssettingsModule;
 import google.registry.keyring.api.KeyModule;
 import google.registry.keyring.api.VoidKeyringModule;
+import google.registry.monitoring.whitebox.StackdriverModule;
 import google.registry.rde.JSchModule;
 import google.registry.request.Modules.AppIdentityCredentialModule;
 import google.registry.request.Modules.DatastoreServiceModule;
@@ -45,30 +46,32 @@ import javax.inject.Singleton;
 /** Dagger component with instance lifetime for "backend" App Engine module. */
 @Singleton
 @Component(
-    modules = {
-        AppIdentityCredentialModule.class,
-        BigqueryModule.class,
-        ConfigModule.class,
-        DatastoreServiceModule.class,
-        DirectoryModule.class,
-        DriveModule.class,
-        GcsServiceModule.class,
-        GoogleCredentialModule.class,
-        GroupsModule.class,
-        GroupssettingsModule.class,
-        JSchModule.class,
-        Jackson2Module.class,
-        KeyModule.class,
-        ModulesServiceModule.class,
-        SpreadsheetServiceModule.class,
-        SystemClockModule.class,
-        SystemSleeperModule.class,
-        URLFetchServiceModule.class,
-        UrlFetchTransportModule.class,
-        UseAppIdentityCredentialForGoogleApisModule.class,
-        VoidDnsWriterModule.class,
-        VoidKeyringModule.class,
-    })
+  modules = {
+    AppIdentityCredentialModule.class,
+    BigqueryModule.class,
+    ConfigModule.class,
+    DatastoreServiceModule.class,
+    DirectoryModule.class,
+    DriveModule.class,
+    GcsServiceModule.class,
+    GoogleCredentialModule.class,
+    GroupsModule.class,
+    GroupssettingsModule.class,
+    JSchModule.class,
+    Jackson2Module.class,
+    KeyModule.class,
+    ModulesServiceModule.class,
+    SpreadsheetServiceModule.class,
+    StackdriverModule.class,
+    SystemClockModule.class,
+    SystemSleeperModule.class,
+    URLFetchServiceModule.class,
+    UrlFetchTransportModule.class,
+    UseAppIdentityCredentialForGoogleApisModule.class,
+    VoidDnsWriterModule.class,
+    VoidKeyringModule.class,
+  }
+)
 interface BackendComponent {
   BackendRequestComponent startRequest(RequestModule requestModule);
 }