Revert^2 "Move some image/9patch code to androidfw"

This reverts commit 917043bc2586743afda5a21386893fa8c787800b.

Reason for revert: Roll forward with fix

Test: Automatic
Bug: 296324826
Change-Id: I42a0b48c02fd497b2174c0c65f300265202f7ab1
diff --git a/tools/aapt2/io/StringStream.cpp b/tools/aapt2/io/StringStream.cpp
index 9c49788..bb3911b 100644
--- a/tools/aapt2/io/StringStream.cpp
+++ b/tools/aapt2/io/StringStream.cpp
@@ -51,6 +51,23 @@
   return str_.size();
 }
 
+bool StringInputStream::ReadFullyAtOffset(void* data, size_t byte_count, off64_t offset) {
+  if (byte_count == 0) {
+    return true;
+  }
+  if (offset < 0) {
+    return false;
+  }
+  if (offset > std::numeric_limits<off64_t>::max() - byte_count) {
+    return false;
+  }
+  if (offset + byte_count > str_.size()) {
+    return false;
+  }
+  memcpy(data, str_.data() + offset, byte_count);
+  return true;
+}
+
 StringOutputStream::StringOutputStream(std::string* str, size_t buffer_capacity)
     : str_(str),
       buffer_capacity_(buffer_capacity),