Cherry-pick following commits from master:

* Add ability to delete file from service
  I7a8c5d09511c4d85483f9cb112550b29039eb05b
* Add metadata version and increment service version in case of modification
  Ib5853938386142edd291e3e005b381c2524c58d5

Change-Id: Ieac59f247ac1886a769dab0f221b59ecae244250