Don't run WebLayer browsertests using an incognito profile on Android.

We weren't passing a profile name so it was always in-memory. I'm using this in a follow-up cl to force all downloads in weblayer_browsertests to go to this temp profile directory instead of filling up the default download folder. It also makes sense that WebLayer Android browser tests match desktop, and non-WebLayer as well.

Bug: 1025603
Change-Id: I1f4fe20e77e6405b97365a9dfa30917fd1c5d486
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1984761Reviewed-by: Clark DuVall <cduvall@chromium.org>
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728010}

weblayer/shell/android/browsertests_apk/src/org/chromium/weblayer_browsertests_apk/WebLayerBrowserTestsActivity.java

@@ -77,7 +77,7 @@ public class WebLayerBrowserTestsActivity extends NativeBrowserTestActivity {
                 new RelativeLayout.LayoutParams(
                         LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
 
-        Fragment fragment = WebLayer.createBrowserFragment(null);
+        Fragment fragment = WebLayer.createBrowserFragment("BrowserTestProfile");
 
         FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
         transaction.add(viewId, fragment);