[Android] Add a custom pylintrc for build/android/.

The default depot_tools pylintrc disables some checks that we can
reasonably enable in build/android/. This CL does so.

BUG=

Review URL: https://codereview.chromium.org/1315743004

Cr-Commit-Position: refs/heads/master@{#347720}
diff --git a/build/android/buildbot/bb_device_steps.py b/build/android/buildbot/bb_device_steps.py
index 2e4c42ef..a1eb1bd 100755
--- a/build/android/buildbot/bb_device_steps.py
+++ b/build/android/buildbot/bb_device_steps.py
@@ -724,6 +724,7 @@
 
   setattr(options, 'target', options.factory_properties.get('target', 'Debug'))
 
+  # pylint: disable=global-statement
   if options.chrome_output_dir:
     global CHROME_OUT_DIR
     global LOGCAT_DIR