Bluetooth: Modify and append to the Out-of-Band API

 - Modify createOutOfBand to be a SystemApi, and accept p192 and p256 data objects.
 - Modify OobData to become a SystemApi and to provide a Builder pattern for creation.

CTS-Coverage-Bug: 182420103
Bug: 178007935
Test: compiles and runs
Tag: #feature
Change-Id: I46aec8c2cb64a8da8957d01d32b879d60df7a31c
Merged-In: I46aec8c2cb64a8da8957d01d32b879d60df7a31c