[client] Add support to run_isolated/cipd for cipd 1.5.

client/run_isolated.py

 #!/usr/bin/env python
 # Copyright 2012 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Runs a command with optional isolated input/output.
 
 Despite name "run_isolated", can run a generic non-isolated command specified as
 args.
 
@@ skipping 745 matching lines @@
       if not site_root.startswith(run_dir):
         raise cipd.Error('Invalid CIPD package path "%s"' % path)
 
       # Do not clean site_root before installation because it may contain other
       # site roots.
       file_path.ensure_tree(site_root, 0770)
       pins = client.ensure(
           site_root, [(name, vers) for name, vers, _ in pkgs],
           cache_dir=cipd_cache_dir,
           timeout=timeoutfn())
-      for i, pin in enumerate(pins):
+      for i, pin in enumerate(pins[""]):
         insert_pin(path, pin[0], pin[1], pkgs[i][2])
       file_path.make_tree_files_read_only(site_root)
 
     total_duration = time.time() - start
     logging.info(
         'Installing CIPD client and packages took %d seconds', total_duration)
 
     assert None not in package_pins
 
     yield CipdInfo(
@@ skipping 230 matching lines @@
     return 1
 
 
 if __name__ == '__main__':
   subprocess42.inhibit_os_error_reporting()
   # Ensure that we are always running with the correct encoding.
   fix_encoding.fix_encoding()
   file_path.enable_symlink()
 
   sys.exit(main(sys.argv[1:]))