Messaging: Use xml drawables

Replace the pngs with xml drawables

Change-Id: I71be32c36194d3b34b54287a09789f73087600ef

res/drawable/ic_checkbox_blank_light.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     SPDX-FileCopyrightText: Material Design Authors / Google LLC
+     SPDX-License-Identifier: Apache-2.0
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFF"
+        android:pathData="M19,3H5C3.89,3 3,3.89 3,5V19A2,2 0 0,0 5,21H19A2,2 0 0,0 21,19V5C21,3.89 20.1,3 19,3Z" />
+</vector>