Increase logging verbosity in GetCoverageRules endpoint.

- More log output to help with debugging.

BUG=b:182898188
TEST=CQ

Change-Id: I95336cd74aad820c53698df2310ac8166d119f5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3082327
Tested-by: Andrew Lamb <andrewlamb@chromium.org>
Auto-Submit: Andrew Lamb <andrewlamb@chromium.org>
Reviewed-by: Sean McAllister <smcallis@google.com>
Commit-Queue: Andrew Lamb <andrewlamb@chromium.org>
diff --git a/api/controller/test.py b/api/controller/test.py
index 0417add..c64eab0 100644
--- a/api/controller/test.py
+++ b/api/controller/test.py
@@ -401,7 +401,7 @@
   build_metadata_list = input_proto.build_metadata_list
   flat_config_list = input_proto.flat_config_list
 
-  cmd = ['testplan', 'generate']
+  cmd = ['testplan', 'generate', '-logtostderr', '-v', '2']
 
   with osutils.TempDir(prefix='get_coverage_rules_input') as tempdir:
     # Write all input files required by testplan, and read the output file