Use CP2 for default account setting in AOSP.

1) read the setting from CP2.
2) add an activity to handle the intent to set the setting
when it's the preloaded contacts app.

Test: manual tests.
Bug: 213629089
Change-Id: Ib8338e9a3c4531eb642d1ee6c6a3cea2546a2dc7
6 files changed