Change to REQUEST from LISTEN for mobile data preferred uids feature

- If Mobile data always on is OFF, mobile data preferred uids
  feature does not work.
- We need to request mobile data when MDO list is not empty.

Bug: 171872461
Test: atest FrameworksNetTests
Test: atest CtsNetTestCases

Signed-off-by: Ansik <ansik.shin@samsung.com>
Original-Change: https://android-review.googlesource.com/1751023
Merged-In: Ie9d6b3e39ef16813c4be3979900d226c8f3d656d
Change-Id: Ie9d6b3e39ef16813c4be3979900d226c8f3d656d
2 files changed