Revert "Escape single quotes in aapt2"

This reverts commit c90f42c8.

Reason for revert: Introduces the escaping *into the APKs*; as mentioned in b/140373430#comment3 the Right Way to dump XML is via textproto.
Fix: 222745626
Bug: 140373430

Change-Id: I775b8a304e76a83934c36886c17cf23560914d21