Add FLAG_RERAIN_PHONE_NUMBER_FORMATTING.

Sometimes using PhoneNumberUtils takes unexpected side effects.
For example, PAUSE mark (#) is removed and operation on the phone number does
not work well in some devices.
I also concern removing the PhoneNumberUtils logic since some other
mobile phones cannot understand # or alphabets and starts emitting errors
after the modification.

I'll add a flag instead of just removing the code and let users choose it.

Bug: 2329952
Change-Id: I4ffdd01ebb8ac320b8b67a5848a747af13c6ad1a