Ignore connectionReady with invalid subscription

While SIM is disabled and enabled again,
if a clients register a callback before IMS service initializes the MMTEL feature connection,
invalid IMS connection state is notified to the client temporarily.

Bug: 227525553
Test: atest TeleServiceTests:ImsStateCallbackControllerTest
Change-Id: I537e63b0f9d401c9e6121fc53fb0287c2cc41aee
2 files changed