Fix AXML parser to handle obfuscated attribute names

This adds an additional check if the attribute namespace belongs to
Android namespace, and if so we try to decode using attribute decoder.

Fixes iBotPeaches#1576.

brut.apktool/apktool-lib/src/main/java/brut/androlib/res/decoder/AXmlResourceParser.java

@@ -339,13 +339,12 @@ public String getAttributeName(int index) {
 
         // some attributes will return "", we must rely on the resource_id and refer to the frameworks
         // to match the resource id to the name. ex: 0x101021C = versionName
-        if (value.length() != 0) {
+        if (value.length() != 0 && !android_ns.equals(getAttributeNamespace(index))) {
             return value;
         } else {
             try {
                 value = mAttrDecoder.decodeManifestAttr(getAttributeNameResource(index));
             } catch (AndrolibException e) {
-                value = "";
             }
             return value;
         }