Fix vCard importer flow.

- call startService() before bindService() to suppress connection
  leakage
- make cancel operation work properly
- take care of cache files appropriately
- add useful logs
- show Toast every time when import started

Note: I still see some connection leakage in ImportVCardActivity.

Bug: 3150402
Bug: 3159855
Change-Id: Iaec6d4e5d8ebcda84e2df5571f87bd3c59e5b264
4 files changed