weblayer: update expectations for testSetUserAgentString

This test uses API added in 84, so it needs to be marked as such.

BUG=1079491
TEST=testSetUserAgentString

Change-Id: I02757559f49359af080bc554c37b334351506dcb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2298042
Auto-Submit: Scott Violet <sky@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#788433}

weblayer/browser/android/javatests/skew/expectations.txt

@@ -28,8 +28,6 @@ crbug.com/1070851 [ impl_lte_83 ] org.chromium.weblayer.test.NavigationTest#test
 # Fixed in https://crrev.com/c/2180022.
 crbug.com/1077243 [ impl_lte_83 ] org.chromium.weblayer.test.FullscreenCallbackTest#testExitFullscreenWhenTabDestroyed [ Skip ]
 
-crbug.com/1079491 [ impl_lte_83 ] org.chromium.weblayer.test.NavigationTest#testSetUserAgentString [ Skip ]
-
 crbug.com/1096570 [ impl_lte_83 ] org.chromium.weblayer.test.ExternalNavigationTest#testExternalIntentWithNoRedirectLaunched [ Skip ]
 
 # -------------------------------------

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/NavigationTest.java

@@ -735,6 +735,7 @@ public class NavigationTest {
 
     @Test
     @SmallTest
+    @MinWebLayerVersion(84)
     public void testSetUserAgentString() throws Exception {
         TestWebServer testServer = TestWebServer.start();
         InstrumentationActivity activity = mActivityTestRule.launchShellWithUrl(null);