releasetools: Clean up the logging while calling external commands.

common.RunAndCheckOutput() checks the exit code and will raise on errors.

Test: python -m unittest test_ota_from_target_files
Test: Call ota_from_target_files.py with aosp_marlin target_files zip
Test: Inject an error to the command. Repeat the call without verbose
      flag. It dumps the stack trace on error.
Change-Id: I85b765a33b9087bcbcb0571d6e632a07bb86c65c