Fix version check and move it to proper place.

Previously, the check only checked whether the get.cm build version was
higher, which gave incorrect results (e.g. 9.0.0.2 was considered newer
than 10.1.0.0 because 2 > 0).

Change-Id: I3cdc0d80bb8f7667705ba72a612e18c07f436bd7
JIRA:CYAN-1200
Don't show notification if check was triggered manually.

We're already in the activity anyway in this case.

Change-Id: I31fcd115c58c8dcebf39d1df1c3156002738e1b7