AAPT2: Fix quoted text in res/xml assets

AAPT2 aggressively processed xml nodes and regressed from the behavior
of AAPT. This change restores AAPT's processing of xml nodes with
quotations.

Bug: 71805084
Test: Created tests in XmlFlattener_test.cpp and ran the test in the
Android Studio project given in the bug

Change-Id: Idedb4f1002e9fd705ceb5feae35289235b754b02
diff --git a/tools/aapt2/format/binary/XmlFlattener.cpp b/tools/aapt2/format/binary/XmlFlattener.cpp
index d897941..2fe2424 100644
--- a/tools/aapt2/format/binary/XmlFlattener.cpp
+++ b/tools/aapt2/format/binary/XmlFlattener.cpp
@@ -79,23 +79,31 @@
   }
 
   void Visit(const xml::Text* node) override {
-    if (util::TrimWhitespace(node->text).empty()) {
-      // Skip whitespace only text nodes.
+    std::string text = util::TrimWhitespace(node->text).to_string();
+
+    // Skip whitespace only text nodes.
+    if (text.empty()) {
       return;
     }
 
+    // Compact leading and trailing whitespace into a single space
+    if (isspace(node->text[0])) {
+      text = ' ' + text;
+    }
+    if (isspace(node->text[node->text.length() - 1])) {
+      text = text + ' ';
+    }
+
     ChunkWriter writer(buffer_);
     ResXMLTree_node* flat_node = writer.StartChunk<ResXMLTree_node>(RES_XML_CDATA_TYPE);
     flat_node->lineNumber = util::HostToDevice32(node->line_number);
     flat_node->comment.index = util::HostToDevice32(-1);
 
-    ResXMLTree_cdataExt* flat_text = writer.NextBlock<ResXMLTree_cdataExt>();
-
     // Process plain strings to make sure they get properly escaped.
-    StringBuilder builder;
-    builder.AppendText(node->text);
-    AddString(builder.to_string(), kLowPriority, &flat_text->data);
+    text = StringBuilder(true /*preserve_spaces*/).AppendText(text).to_string();
 
+    ResXMLTree_cdataExt* flat_text = writer.NextBlock<ResXMLTree_cdataExt>();
+    AddString(text, kLowPriority, &flat_text->data);
     writer.Finish();
   }