Remove the flaky Conditionals test.

This test seems to be flaky for quite a while. The method tested runs
the check using a FutureTask which may sometimes hit the timeout issue,
so it seems not that suitable to do the test.

Fixes: 176274700
Test: robotest
Change-Id: I1bf979f4a792d76da01bfa82355ccf8f659dc6f8

tests/robotests/src/com/android/settings/homepage/contextualcards/conditional/ConditionManagerTest.java

@@ -66,13 +66,6 @@ public class ConditionManagerTest {
         assertThat(mManager.getDisplayableCards()).isEmpty();
     }
 
-    @Test
-    public void getDisplayableCards_hasDisplayable() {
-        when(mController.isDisplayable()).thenReturn(true);
-
-        assertThat(mManager.getDisplayableCards()).hasSize(1);
-    }
-
     @Test
     public void onPrimaryClick_shouldRelayToController() {
         mManager.onPrimaryClick(mContext, ID);