KeyChain: Adding methods for user-visibility.

Add to the KeyChain aidl two methods for getting and setting whether
a key can be selectable by the user or not.

See
https://googleplex-android-review.git.corp.google.com/#/c/platform/packages/apps/KeyChain/+/3199414/

Test: To be determined.
Bug: 65624467
Change-Id: Ib31a11ca432a5d29fdb8ed5349598dbff4bcb516
diff --git a/keystore/java/android/security/IKeyChainService.aidl b/keystore/java/android/security/IKeyChainService.aidl
index c4bb72c..635432d 100644
--- a/keystore/java/android/security/IKeyChainService.aidl
+++ b/keystore/java/android/security/IKeyChainService.aidl
@@ -28,6 +28,8 @@
     String requestPrivateKey(String alias);
     byte[] getCertificate(String alias);
     byte[] getCaCertificates(String alias);
+    boolean isUserSelectable(String alias);
+    void setUserSelectable(String alias, boolean isUserSelectable);
 
     // APIs used by CertInstaller and DevicePolicyManager
     String installCaCertificate(in byte[] caCertificate);