cbuildbot: Move Buildbot printing functions to `cbuildbot_alerts` module

Move all of the cbuildbot-specific printing routines out of cros_logging
and in to a new submodule of cbuildbot. Fix up all usages of these
functions to point to the new location.

BUG=b:191490453
TEST=`run_tests`

Change-Id: I5f5f28256b89d2b0500c1c404e2718f33aceaa31
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2973409
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/upload_symbols_unittest.py b/scripts/upload_symbols_unittest.py
index fcc56b3..4470e5f 100644
--- a/scripts/upload_symbols_unittest.py
+++ b/scripts/upload_symbols_unittest.py
@@ -45,7 +45,7 @@
     break
 del third_party
 
-from chromite.lib import cros_logging as logging
+from chromite.cbuildbot import cbuildbot_alerts
 from chromite.lib import cros_test_lib
 from chromite.lib import osutils
 from chromite.lib import parallel
@@ -339,7 +339,8 @@
     self.slim = self.createSymbolFile('slim.sym', self.SLIM_CONTENT)
     self.fat = self.createSymbolFile('fat.sym', self.FAT_CONTENT)
 
-    self.warn_mock = self.PatchObject(logging, 'PrintBuildbotStepWarnings')
+    self.warn_mock = self.PatchObject(cbuildbot_alerts,
+                                      'PrintBuildbotStepWarnings')
 
   def _testNotStripped(self, symbol, size=None, content=None):
     start_file = symbol.file_name