Change TelephonyConnection to use onDisconnect callback from original conn.

In the past TelephonyConnection registered for disconnect from the phone
class and used this as a trigger to update its internal state.
We are now favoring a direct callback from the original connection.
This makes disconnects easier to trace and more reliable.

Test: Manual
Bug: 70389936
Change-Id: I1983b6f1da46fa7a33347ee47096c640847d73c2
1 file changed