[Wi-Fi] Add basic UI structure for adding Wi-Fi for apps feature.

Add following changes:
1. Add intent receiver.
2. Add panel UI with icon, title, summary.
3. Add two buttons (save and cancel).
4. Add test case for activity and fragment

Bug: 136472483
Test: Add following test cases for checking button and package name in activity and fragment.
      1. AddAppNetworksActivityTest
      2. AddAppNetworksFragmentTest
Change-Id: I5515a96fa3feb0e3e6d68159b2c0dec0894c15ee