Don't preload AsYouTypeFormatter

- This took 200ms of startup time at least, and a lot more under heavy load,
  especially when the flash is busy.  (200ms is mostly disk I/O.)

- Instead, make sure we always use AsyncTask to create
  PhoneNumberFormattingTextWatcher, which wass the only thing that uses
  AsYouTypeFormatter.

- DialpadFragment already had an AsnycTask.  Moved it to the new class UiUtils
  and use it in TextFieldsEditorView, which is the only other callsite.

- Also improved the logging for account loading.  We used to log only CPU
  time, but what we really care is the actual wall time.  Because
  account loading involves a lot of file access (e.g. loading 3rd party
  apks), only measuring CPU time is not too useful.
  (In fact, on my phone, loading accounts takes only 50ms CPU time but
  >500ms wall time.)

Bug 5195464

Change-Id: I2b51e864d75831bdbb9e424aa846133d49d6ef94