[TTS] Conditionally reenable a disabled flaky test

Reenable testLongpressExtendinSelectionExactResolve which was disabled
due to flakes.  It's an important test of a new feature, so bringing
it back in a limited way.

It looks pretty solid on non-tablet M+.

TBR=mastiz@chromium.org

BUG=1048827

Change-Id: I5c3878a3e5059b71b9eebae6af43bd1e7158b273
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042377Reviewed-by: Donn Denman <donnd@chromium.org>
Commit-Queue: Donn Denman <donnd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739075}

chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java

@@ -3228,11 +3228,15 @@ public class ContextualSearchManagerTest {
     }
 
     @Test
-    @DisabledTest(message = "See https://crbug.com/1048827")
     @SmallTest
-    @Feature({"ContextualSearch"})
-    @Features.EnableFeatures("ContextualSearchLongpressResolve")
-    public void testLongpressExtendinSelectionExactResolve() throws TimeoutException {
+    @Restriction(UiRestriction.RESTRICTION_TYPE_PHONE)
+    @DisableIf
+            .Build(sdk_is_less_than = Build.VERSION_CODES.M,
+                    message = "Flaky < M, https://crbug.com/1048827")
+            @Feature({"ContextualSearch"})
+            @Features.EnableFeatures("ContextualSearchLongpressResolve")
+            public void
+            testLongpressExtendinSelectionExactResolve() throws TimeoutException {
         // First test regular long-press.  It should not require an exact resolve.
         longPressNode("search");
         fakeAResponse();