[ShapeableImageView] Improve default style

PiperOrigin-RevId: 313428562
(cherry picked from commit efc0a7f)

Author: ymarian

lib/java/com/google/android/material/color/res/color/material_on_surface_stroke.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright 2020 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.
+-->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+  <item android:alpha="0.12" android:color="?attr/colorOnSurface" />
+</selector>

lib/java/com/google/android/material/imageview/res/values/styles.xml

@@ -18,7 +18,8 @@
 <resources>
 
   <style name="Widget.MaterialComponents.ShapeableImageView" parent="android:Widget">
-    <item name="strokeColor">?attr/colorAccent</item>
+    <item name="strokeColor">@color/material_on_surface_stroke</item>
+    <item name="shapeAppearance">?attr/shapeAppearanceMediumComponent</item>
   </style>
 
 </resources>