Splitting over-the-air downloading into batches

Splitting the over-the-air downloading of contacts into batches to ameliorate PBAP crash when system goes to S2R while download is in progress.

Test: Use ACTS/SL4A: act.py -c <test_config>.json -tc BtCarPbapTest:test_contact_download

Bug: b/117588939
Change-Id: I7d138a7d497c04c54710702320ba1fdea8f15ea7
(cherry picked from commit 1128539a)

Merged-In: I7d138a7d497c04c54710702320ba1fdea8f15ea7
Change-Id: Idd1b1b5b22360ab36b05ddfbf62e5043e873098d