Improve dialer's background

See a before/after comparison (exposure boosted to highlight the diff):
http://www/~romainguy/no_crawl/newgradients.png

Change-Id: Ifea32165e438841210d48220a16549ce3e0b6d27
diff --git a/res/drawable-nodpi/background_dial_holo_dark.png b/res/drawable-nodpi/background_dial_holo_dark.png
deleted file mode 100644
index 3dba50c..0000000
--- a/res/drawable-nodpi/background_dial_holo_dark.png
+++ /dev/null
Binary files differ
diff --git a/res/drawable/background_dial_holo_dark.xml b/res/drawable/background_dial_holo_dark.xml
new file mode 100644
index 0000000..e06507f
--- /dev/null
+++ b/res/drawable/background_dial_holo_dark.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2012 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <gradient
+            android:startColor="#ff020709"
+            android:endColor="#ff0a242d"
+            android:angle="270" />
+</shape>