add patch grid update for 64 bit arm

TBR=
NOTREECHECKS=true
NOTRY=true

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/463353003
diff --git a/expectations/gm/Test-Android-Reference-Unknown-Arm64-Release/expected-results.json b/expectations/gm/Test-Android-Reference-Unknown-Arm64-Release/expected-results.json
index b8d54d7..4973edd 100644
--- a/expectations/gm/Test-Android-Reference-Unknown-Arm64-Release/expected-results.json
+++ b/expectations/gm/Test-Android-Reference-Unknown-Arm64-Release/expected-results.json
@@ -8491,7 +8491,7 @@
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          7228204456936434724
+          5520583909201375586
         ]
       ], 
       "reviewed-by-human": true