xbuddy: Remove xbuddy files from platform.

Delete the following files:
android_build.py
artifact_info.py
build_artifact.py
build_artifact_unittest.py
build_util.py
common_util.py
common_util_unittest.py
devserver_constants.py
downloader.py
downloader_unittest.py
log_util.py
retry.py
xbuddy.py
xbuddy_unittest.py
shadow_xbuddy_config.ini
xbuddy_config.ini

Update the imports in the following files:
autoupdate.py
autoupdate_unittest.py
builder.py
cros_update_progress.py
devserver.py
devserver_integration_test.py
health_checker.py

Rename log_util.py to cherrypy_log_util.py

Remove files from Makefile

Fix lint errors in builder.py

Patchset 1 is the file deletion, subsequent patchsets have code changes.

BUG=chromium:1003986
TEST=unittests, cros flash, devserver_integration_test

Cq-Depend: chromium:1894475
Change-Id: I4e70d0971eda00263a69906a6c1b11a3014d947c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1893644
Tested-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
diff --git a/devserver.py b/devserver.py
index 2d156f3..eeb5418 100755
--- a/devserver.py
+++ b/devserver.py
@@ -46,49 +46,29 @@
 from cherrypy.process import plugins
 # pylint: enable=no-name-in-module, import-error
 
+import autoupdate
+import cherrypy_ext
+import cros_update
+import cros_update_progress
+import health_checker
+
 # This must happen before any local modules get a chance to import
 # anything from chromite.  Otherwise, really bad things will happen, and
 # you will _not_ understand why.
 import setup_chromite  # pylint: disable=unused-import
+from chromite.lib.xbuddy import android_build
+from chromite.lib.xbuddy import artifact_info
+from chromite.lib.xbuddy import build_artifact
+from chromite.lib.xbuddy import cherrypy_log_util
+from chromite.lib.xbuddy import common_util
+from chromite.lib.xbuddy import devserver_constants
+from chromite.lib.xbuddy import downloader
+from chromite.lib.xbuddy import xbuddy
 
-import artifact_info
-import autoupdate
-import build_artifact
-import cherrypy_ext
-import common_util
-import devserver_constants
-import downloader
-import health_checker
-import log_util
-import xbuddy
 
 # Module-local log function.
 def _Log(message, *args):
-  return log_util.LogWithTag('DEVSERVER', message, *args)
-
-
-# Use try-except to skip unneccesary import for simple use case, eg. running
-# devserver on host.
-try:
-  import cros_update
-except ImportError as e:
-  _Log('cros_update cannot be imported: %r', e)
-  cros_update = None
-
-try:
-  import cros_update_progress
-except ImportError as e:
-  _Log('cros_update_progress cannot be imported: %r', e)
-  cros_update_progress = None
-
-try:
-  import android_build
-except ImportError:
-  # Ignore android_build import failure. This is to support devserver running
-  # inside a ChromeOS device triggered by cros flash. Most ChromeOS test images
-  # do not have google-api-python-client module and they don't need to support
-  # Android updating, therefore, ignore the import failure here.
-  android_build = None
+  return cherrypy_log_util.LogWithTag('DEVSERVER', message, *args)
 
 CACHED_ENTRIES = 12