Add getProfileParentId (1/2)

Bluetooth service needs to natively access id of parent profile. Add
method exposing it.

Test: cts-tradefed run cts-dev -m DevicePolicyManager --test
com.android.cts.devicepolicy.ManagedProfileTest#testBluetooth
Bug: 69284968
Change-Id: I697906f2959b0736c1d3cc6af7560c27d77ce11b

core/java/android/os/IUserManager.aidl

@@ -35,6 +35,10 @@ interface IUserManager {
      * DO NOT MOVE - UserManager.h depends on the ordering of this function.
      */
     int getCredentialOwnerProfile(int userHandle);
+    int getProfileParentId(int userHandle);
+    /*
+     * END OF DO NOT MOVE
+     */
 
     UserInfo createUser(in String name, int flags);
     UserInfo createProfileForUser(in String name, int flags, int userHandle,

services/core/java/com/android/server/pm/UserManagerService.java

@@ -714,6 +714,19 @@ public class UserManagerService extends IUserManager.Stub {
         }
     }
 
+    @Override
+    public int getProfileParentId(int userHandle) {
+        checkManageUsersPermission("get the profile parent");
+        synchronized (mUsersLock) {
+            UserInfo profileParent = getProfileParentLU(userHandle);
+            if (profileParent == null) {
+                return userHandle;
+            }
+
+            return profileParent.id;
+        }
+    }
+
     private UserInfo getProfileParentLU(int userHandle) {
         UserInfo profile = getUserInfoLU(userHandle);
         if (profile == null) {