Add CTS tests for Remove Result error code

Bug: 215555912
Test: atest UserManagerTest
Change-Id: Ib78cfa6e04afcc2029cda8a16df68b7d25548a1d
diff --git a/tests/tests/multiuser/src/android/multiuser/cts/UserManagerTest.java b/tests/tests/multiuser/src/android/multiuser/cts/UserManagerTest.java
index 8aa4e7f..025e8ef 100644
--- a/tests/tests/multiuser/src/android/multiuser/cts/UserManagerTest.java
+++ b/tests/tests/multiuser/src/android/multiuser/cts/UserManagerTest.java
@@ -108,6 +108,28 @@
     }
 
     @Test
+    public void testIsRemoveResultSuccessful() {
+        assertThat(UserManager.isRemoveResultSuccessful(UserManager.REMOVE_RESULT_REMOVED))
+                .isTrue();
+        assertThat(UserManager.isRemoveResultSuccessful(UserManager.REMOVE_RESULT_DEFERRED))
+                .isTrue();
+        assertThat(UserManager
+                .isRemoveResultSuccessful(UserManager.REMOVE_RESULT_ALREADY_BEING_REMOVED))
+                        .isTrue();
+        assertThat(UserManager.isRemoveResultSuccessful(UserManager.REMOVE_RESULT_ERROR_UNKNOWN))
+                .isFalse();
+        assertThat(UserManager
+                .isRemoveResultSuccessful(UserManager.REMOVE_RESULT_ERROR_USER_RESTRICTION))
+                        .isFalse();
+        assertThat(UserManager
+                .isRemoveResultSuccessful(UserManager.REMOVE_RESULT_ERROR_USER_NOT_FOUND))
+                        .isFalse();
+        assertThat(
+                UserManager.isRemoveResultSuccessful(UserManager.REMOVE_RESULT_ERROR_SYSTEM_USER))
+                        .isFalse();
+    }
+
+    @Test
     public void testIsHeadlessSystemUserMode() throws Exception {
         boolean expected = getBooleanProperty(mInstrumentation,
                 "ro.fw.mu.headless_system_user");