Update zlib fingerprint with zlib version 1.2.11.

I reviewed the code changes, there's no compression algorithm changes
except level 0 which imgdiff does not support (it only support level 6
and 9).

I also compressed a few files and compared the result with 1.2.8, and
the files are exactly the same.

Test: update_engine_unittests
Change-Id: Iedc3bf5e08c0d5431acb67f4180cf40a6b5012db
diff --git a/payload_consumer/payload_constants.cc b/payload_consumer/payload_constants.cc
index 6078a74..60b857e 100644
--- a/payload_consumer/payload_constants.cc
+++ b/payload_consumer/payload_constants.cc
@@ -40,6 +40,8 @@
 const char kCompatibleZlibFingerprint[][65] = {
     "ea973605ccbbdb24f59f449c5f65861a1a9bc7a4353377aaaa06cb3e0f1cfbd7",
     "3747fa404cceb00a5ec3606fc779510aaa784d5864ab1d5c28b9e267c40aad5c",
+    // zlib 1.2.11
+    "61514794a2985bee78135fd67a2f1fd18e56f3c3e410fbc4552a0e05a701e47a",
 };
 
 const char* InstallOperationTypeName(InstallOperation_Type op_type) {