Revert of Restrict ModalDialogTest#testPromptModalDialog to non-low-end...

Revert of Restrict ModalDialogTest#testPromptModalDialog to non-low-end devices (patchset #1 id:1 of https://codereview.chromium.org/2397573008/ )

Reason for revert:
Root cause is in Android framework, we're just going to catch the exception

Original issue's description:
> Restrict ModalDialogTest#testPromptModalDialog to non-low-end devices
>
> BUG=653685
> TBR=carlosk@chromium.org, dfalcantara@chromium.org
>
> Committed: https://crrev.com/3988c1fd1bc405d01850a8e5e28619d0630b5184
> Cr-Commit-Position: refs/heads/master@{#423709}

TBR=carlosk@chromium.org,dfalcantara@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=653685

Review-Url: https://codereview.chromium.org/2396243002
Cr-Commit-Position: refs/heads/master@{#423743}

chrome/android/javatests/src/org/chromium/chrome/browser/ModalDialogTest.java

@@ -4,8 +4,6 @@
 
 package org.chromium.chrome.browser;
 
-import static org.chromium.base.test.util.Restriction.RESTRICTION_TYPE_NON_LOW_END_DEVICE;
-
 import android.content.DialogInterface;
 import android.support.v7.app.AlertDialog;
 import android.test.suitebuilder.annotation.MediumTest;
@@ -17,7 +15,6 @@ import android.widget.EditText;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
-import org.chromium.base.test.util.Restriction;
 import org.chromium.base.test.util.RetryOnFailure;
 import org.chromium.base.test.util.UrlUtils;
 import org.chromium.chrome.R;
@@ -140,7 +137,6 @@ public class ModalDialogTest extends ChromeActivityTestCaseBase<ChromeActivity>
      */
     @MediumTest
     @Feature({"Browser", "Main"})
-    @Restriction({RESTRICTION_TYPE_NON_LOW_END_DEVICE}) // crbug.com/653685
     public void testPromptModalDialog()
             throws InterruptedException, TimeoutException, ExecutionException {
         final String promptText = "Hello Android!";