Add listeners to observe role holders changes.

This change adds the ability to add listeners to observe role holder
changes. This will be used by the new role management UI and other
system components that used to put the default app in settings and
observe settings change.

Bug: 110557011
Test: manual
Change-Id: I2a8eb39220081e3be801adb970b60c55ebc297c7
diff --git a/Android.bp b/Android.bp
index 2c5fc4e..a4d3d33 100644
--- a/Android.bp
+++ b/Android.bp
@@ -104,6 +104,7 @@
         "core/java/android/app/backup/IRestoreObserver.aidl",
         "core/java/android/app/backup/IRestoreSession.aidl",
         "core/java/android/app/backup/ISelectBackupTransportCallback.aidl",
+        "core/java/android/app/role/IOnRoleHoldersChangedListener.aidl",
         "core/java/android/app/role/IRoleManager.aidl",
         "core/java/android/app/role/IRoleManagerCallback.aidl",
         "core/java/android/app/slice/ISliceManager.aidl",