Make PRESUBMIT.py run checks via 'pcg' if it is available in PATH.

pre-commit-go.yml

 # https://github.com/maruel/pre-commit-go configuration file to run checks
 # automatically on commit, on push and on continuous integration service after
 # a push or on merge of a pull request.
 #
 # See https://godoc.org/github.com/maruel/pre-commit-go/checks for more
 # information.
 
 coverage_settings: &COVERAGE_SETTINGS
   use_global_inference: false
   use_coveralls: false
@@ skipping 27 matching lines @@
     max_duration: 120
   lint:
     checks:
       errcheck:
       - ignores: Close
       golint:
       - blacklist: []
       govet:
       - blacklist:
         - ' composite literal uses unkeyed fields'
-    max_duration: 15
+    max_duration: 20
   pre-commit:
     checks:
       build:
       - build_all: false
         extra_args: []
       gofmt:
       - {}
       test:
       - extra_args:
         - -short
-    max_duration: 5
+    max_duration: 10
   pre-push:
     checks:
       coverage:
       - <<: *COVERAGE_SETTINGS
       goimports:
       - {}
       test:
       - extra_args:
         - -v
         - -race
-    max_duration: 15
+    max_duration: 20
+
 ignore_patterns:
 - .*
 - _*
 - '*.pb.go'
 - '*_string.go'