IMS phone instantiation: add polling on base phone creation

Phone registers for notification of IMS service up and down. However,
there may be a race condition which causes the phone to be created after
the intents are alrady sent. Add polling in addition to listening to
broadcast intent.

Bug: 19447972
Change-Id: I0e12118bb11a22161cf2f389b9ca6f39442202e1