servicemanager: notifications

You can now register and receive notifications for new services.

Eye towards:
- avoiding while(true) getService loops
- need it to make AIDL dynamic HALs
- need it for feature parity w/ HIDL

Bug: 136027762
Test: servicemanager_test
Change-Id: Iffbf984e87214aa9c9b7af8a5ae682e127ba40a5
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 027418a..86f19c5 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -145,6 +145,7 @@
     name: "libbinder_aidl",
     srcs: [
         "aidl/android/content/pm/IPackageManagerNative.aidl",
+        "aidl/android/os/IServiceCallback.aidl",
         "aidl/android/os/IServiceManager.aidl",
     ],
     path: "aidl",