cros_build_lib: rename RunCommand to run

This aligns with the new subprocess.run API.

RunCommand -> run.
SudoRunCommand -> sudo_run.
DebugRunCommand -> dbg_run.

BUG=chromium:1006587
TEST=`./run_tests` passes

Change-Id: I78ebd4e08176d7874b3d3fe537b6ceb292b0241b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1818782
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
diff --git a/scripts/autotest_quickmerge_unittest.py b/scripts/autotest_quickmerge_unittest.py
index 8b8d4c3..5d485a1 100644
--- a/scripts/autotest_quickmerge_unittest.py
+++ b/scripts/autotest_quickmerge_unittest.py
@@ -115,7 +115,7 @@
   """Test autotest_quickmerge.RsyncQuickmerge."""
 
   def testRsyncQuickmergeCommand(self):
-    """Test that RsyncQuickMerge makes correct call to SudoRunCommand"""
+    """Test that RsyncQuickMerge makes correct call to sudo_run"""
     include_file_name = 'an_include_file_name'
     source_path = 'a_source_path'
     sysroot_path = 'a_sysroot_path'