Integrate IKeystoreUserManager aidl with LockSettingsService.

This CL introduces the client side for IKeystoreUserManager aidl and
integrates it with the LockSettingsService.

Bug: 171305115
Test: TBD
Change-Id: I7560e98f95aaec6b85cdcfc01ba83aea0ccc52ae
diff --git a/Android.bp b/Android.bp
index 4f248d9..88ed676 100644
--- a/Android.bp
+++ b/Android.bp
@@ -525,6 +525,7 @@
         "android.hardware.vibrator-V1.3-java",
         "android.security.apc-java",
         "android.security.authorization-java",
+        "android.security.usermanager-java",
         "android.system.keystore2-V1-java",
         "android.system.suspend.control.internal-java",
         "devicepolicyprotosnano",