[WebLayer] Fix flakes in SiteSettingsTest#testSingleSiteLocationAccess

The test was failing because some Nexus5X test runners have location
access disabled system-wide, which disabled the UI the test was trying
to verify. The fix is to force the location service enabled at the
beginning of the test.

Bug: 1128184
Change-Id: I4166f2147ede1b2aa1d6f46684ba0a84507be31c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2638783Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845224}

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

@@ -17,6 +17,7 @@ import static org.hamcrest.core.StringContains.containsString;
 import android.app.Activity;
 import android.app.Instrumentation.ActivityResult;
 import android.content.Intent;
+import android.os.RemoteException;
 import android.provider.Settings;
 
 import androidx.test.espresso.intent.Intents;
@@ -30,6 +31,7 @@ import org.junit.runner.RunWith;
 
 import org.chromium.weblayer.SettingsTestUtils;
 import org.chromium.weblayer.SiteSettingsActivity;
+import org.chromium.weblayer.TestWebLayer;
 
 /**
  * Tests the behavior of the Site Settings UI.
@@ -105,9 +107,12 @@ public class SiteSettingsTest {
 
     @Test
     @SmallTest
-    public void testSingleSiteLocationAccess() throws InterruptedException {
+    public void testSingleSiteLocationAccess() throws InterruptedException, RemoteException {
         try {
             Intents.init();
+            TestWebLayer testWebLayer =
+                    TestWebLayer.getTestWebLayer(mSettingsTestRule.getContext());
+            testWebLayer.setSystemLocationSettingEnabled(true);
             mSettingsTestRule.launchActivity(
                     SettingsTestUtils.createIntentForSiteSettingsSingleWebsite(
                             mSettingsTestRule.getContext(), PROFILE_NAME, /*isIncognito=*/false,