Remove dead code in StringPool.

The sorted string pool option was no longer used.
Neither were strings with associated identifiers.

Change-Id: Ic5f6368637fbeedfda873d63f4ad0f3ea9d0d603
diff --git a/tools/aapt/XMLNode.cpp b/tools/aapt/XMLNode.cpp
index 8d7acee..0dba950 100644
--- a/tools/aapt/XMLNode.cpp
+++ b/tools/aapt/XMLNode.cpp
@@ -973,7 +973,7 @@
 status_t XMLNode::flatten(const sp<AaptFile>& dest,
         bool stripComments, bool stripRawValues) const
 {
-    StringPool strings = StringPool(false, mUTF8);
+    StringPool strings(mUTF8);
     Vector<uint32_t> resids;
     
     // First collect just the strings for attribute names that have a