Fix tests in UserDetailsSettingsTest and TimeoutToDockUserPreferenceControllerTest

Bug: 313530297
Test: atest UserDetailsSettingsTest && atest TimeoutToDockUserPreferenceControllerTest
Flag: EXEMPT fixing tests that were failing before
Change-Id: Ic4bd257aa26c6627d271acd1f22b59855bbddb20

tests/robotests/testutils/com/android/settings/testutils/shadow/ShadowUserManager.java

@@ -362,6 +362,10 @@ public class ShadowUserManager extends org.robolectric.shadows.ShadowUserManager
         }
     }
 
+    @Implementation
+    protected boolean isAdminUser() {
+        return getUserInfo(UserHandle.myUserId()).isAdmin();
+    }
     @Implementation
     protected boolean isGuestUser() {
         return mIsGuestUser;