Add MOBILE_DATA_POLICY_AUTO_DATA_SWITCH

The feature only applies to non-DDS. If enabled, we automatically switch to the non-DDS for data traffic when it has better availability than the DDS.

Test: cts
Bug: 244064524
Merged-In: Id827b3e253b637273504d87c8db64893c7b70924
Change-Id: Id827b3e253b637273504d87c8db64893c7b70924