Revert to using system AlertDialog.Builder.

Revert to using system AlertDialog.Builder.

Due to b/20882793 bug in AppCompat we need to use system AlertDialog.Builder
for all the dialogs that contain EditText.

BUG=484658
Committed: https://crrev.com/7894f1a861c1256a7d0c43daf4ce641e5b9b6f9e
Cr-Commit-Position: refs/heads/master@{#329688}

[aurimas (slooooooooow), 2015-05-13 01:05:00]

aurimas@chromium.org changed reviewers:
+ dfalcantara@chromium.org

[aurimas (slooooooooow), 2015-05-13 01:05:01]

PTAL.

This makes all to homescreen dialog holo again for pre-L devices.

[gone, 2015-05-13 17:46:11]

lgtm

[aurimas (slooooooooow), 2015-05-13 17:47:27]

The CQ bit was checked by aurimas@chromium.org

[commit-bot: I haz the power, 2015-05-13 17:49:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128683004/1

[commit-bot: I haz the power, 2015-05-13 18:17:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-05-13 18:17:51]

Try jobs failed on following builders:
  android_compile_dbg on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_compile...)

[aurimas (slooooooooow), 2015-05-13 18:21:44]

The CQ bit was checked by aurimas@chromium.org

[aurimas (slooooooooow), 2015-05-13 18:21:44]

The patchset sent to the CQ was uploaded after l-g-t-m from
dfalcantara@chromium.org
Link to the patchset: https://chromiumcodereview.appspot.com/1128683004/#ps20001
(title: "Fix the test")

[commit-bot: I haz the power, 2015-05-13 18:23:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128683004/20001

[commit-bot: I haz the power, 2015-05-13 18:55:57]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-13 18:56:48]

Patchset 2 (id:??) landed as
https://crrev.com/7894f1a861c1256a7d0c43daf4ce641e5b9b6f9e
Cr-Commit-Position: refs/heads/master@{#329688}