Camera: Cache service connections during extension query

Hold on to the service binder connections when checking
individual extension types. Connecting and releasing
the binder connection at each iteration can add some
unnecessary IPC traffic.

Flag: EXEMPT bugfix
Bug: 418699020
Test: Manual using camera application,
Camera CTS

Change-Id: Id31e370b85276df5bc2a63cec149d4d8f51923b8