code: def get_build_tool_version(self):
      
      with open('%s/%s/build.gradle' % (self.path, self.src_folder)) as f:
        for line in f.readlines():
          if 'buildToolsVersion' in line:
            matches = re.findall(r'buildToolsVersion \"(.+?)\"', line)
            if len(matches) == 1:
              return matches[0]
      return config.build_tool_version
docs: Gets the build tool version to be used by zipalign from build.gradle file.
  
      Returns:
        A string containing the build tool version, default is 23.0.2.