Made the follwing changes based on API council review
feedback
1. Made the class and its Builder class final
2. Removed methods that should not be in the builder
3. Changed the return type of available services
from array to list.
Test: Unit tests
Bug 127657991
Change-Id: I3c2d406fed3ddaf62dee193c7657caf8c5bc13d2
20d71403b8