Skip CompressCheckerboard unit test on N6.

This is at least one of the failures making the bot red.
The particular signal indicates it's probably an alignment problem.

BUG=skia:5637
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2245063002

CQ_INCLUDE_TRYBOTS=master.client.skia.android:Test-Android-GCC-Nexus6-CPU-NEON-Arm7-Debug-Trybot

TBR=robertphillips@google.com

Review-Url: https://codereview.chromium.org/2245063002

infra/bots/recipes/swarm_test.expected/Test-Android-GCC-Nexus6-GPU-Adreno420-Arm7-Debug.json

@@ -834,7 +834,9 @@
       "_",
       "image",
       "_",
-      ".SRW"
+      ".SRW",
+      "--match",
+      "~CompressCheckerboard"
     ],
     "env": {
       "ANDROID_HOME": "[SLAVE_BUILD]/android_sdk/android-sdk",
@@ -946,4 +948,4 @@
     "recipe_result": null,
     "status_code": 0
   }
-]
+]

infra/bots/recipes/swarm_test.py

@@ -286,6 +286,9 @@ def dm_flags(bot):
   if 'Valgrind' in bot: # skia:3021
     match.append('~Threaded')
 
+  if 'Nexus6' in bot:  # skia:5637
+    match.append('~CompressCheckerboard')
+
   if 'GalaxyS3' in bot:  # skia:1699
     match.append('~WritePixels')