Add ability to obtain themed Drawable from Context

This is to fix the rendering in layoutlib broken due to
8eea3ea5591e59f55cbb4f6b2b7e9363a285ced3

Change-Id: I3da6691ad86502bd4fa4b302deb381a840b94655
diff --git a/tools/layoutlib/bridge/src/android/content/res/BridgeResources.java b/tools/layoutlib/bridge/src/android/content/res/BridgeResources.java
index c3e06d2..dd573be 100644
--- a/tools/layoutlib/bridge/src/android/content/res/BridgeResources.java
+++ b/tools/layoutlib/bridge/src/android/content/res/BridgeResources.java
@@ -155,6 +155,11 @@
 
     @Override
     public Drawable getDrawable(int id) throws NotFoundException {
+        return getDrawable(id, null);
+    }
+
+    @Override
+    public Drawable getDrawable(int id, Theme theme) {
         Pair<String, ResourceValue> value = getResourceValue(id, mPlatformResourceFlag);
 
         if (value != null) {