Added a new URI updating preferred APN w/o change notification

Solving the issue that setting preferred APN from GDCT triggers
back APN change event and force unnecessary data call disconnects
and setups.

This patch adds one new URI used for preferred APN entry without
causing change notification via ContentObserver.

Bug:5448858
Change-Id: I2c132f367188b9a9da797fec65b3ff974c59a1b4
1 file changed