Change launcher and shortcut icons to MaskableIconDrawable

Test: manual test on Launcher3
Bug: 33034275
Bug: 35431198

Change-Id: Ief9f49ec38ec95daa738799398fc4b458d634acc

res/layout/shortcut_badge_maskable.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 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.
+-->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="@dimen/shortcut_size_maskable"
+    android:layout_height="@dimen/shortcut_size_maskable"
+    android:background="@color/shortcut_background">
+    <Space
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+      android:layout_weight="22"/>
+    <ImageView
+        android:id="@android:id/icon"
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:tint="@color/icon_accent"
+        android:scaleType="fitCenter"
+        android:layout_weight="16"/>
+    <Space
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:layout_weight="22"/>
+</LinearLayout>