Add unit test for commit "Support work contacts in HFP, PBAP, MAP"

1. In ag/674009, entire bluetooth is diabled temporarily.
This commits enable the test and just comment out test case that need the removed dependency.

2. Fixed a potential NPE in composeAndSendPhonebookOneVcard

3. Refactor the code a bit to allow testing

Bug: 19551175
Change-Id: I20e17d38cebdccc39c14e960503ac7d23a9bd928