cryptohome: Convet all *Stub classes into Fake* classes

ShillProfileClientStub is renamed to FakeShillProfileClient.
ShillServiceClientStub is renamed to FakeShillServiceClient
ShillManagerClientStub is renamed to FakeShillManagerClient,
and the original FakeShillManagerClient is removed.

BUG=309506
TEST=none

Review URL: https://codereview.chromium.org/31773002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229770 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229770