Enable Error Prone to detect obscure bugs.

We've been writing many new framework-specific Error Prone checkers
to help detect obscure platform bugs, and this change starts enabling
those checkers for more packages across the platform.

Bug: 155703208
Test: manual
Exempt-From-Owner-Approval: trivial blueprint changes
Change-Id: I1db3412b0be40f6f78c68331ae01756887192071
diff --git a/services/appwidget/Android.bp b/services/appwidget/Android.bp
index 83a9aa4..e46e5c8 100644
--- a/services/appwidget/Android.bp
+++ b/services/appwidget/Android.bp
@@ -7,7 +7,7 @@
 
 java_library_static {
     name: "services.appwidget",
-    defaults: ["services_defaults"],
+    defaults: ["platform_service_defaults"],
     srcs: [":services.appwidget-sources"],
     libs: ["services.core"],
 }