Remove mDeviceOwnerName - it's never read

And remove all the code whose only effect is modifying this unused
variable.

Bug: 219944571
Test: compiles
Change-Id: Ie484c4dcd3691e427365382b447e6d5a86f95cf4
Merged-In: Ie484c4dcd3691e427365382b447e6d5a86f95cf4
(cherry picked from commit 8a168e8a)