refactor(call): star connecting after the callee is changed

Before:
- users need to press the connect button to start peer connection

After:
- users is not required to press connect button anymore, the peer connection is starting after the callee changed
fix(room view): put back the remote video container
Merge branch 'refactor-the-connecting-step' into release-0.3.12
chore(changelog): update changelog for v0.3.13
0.3.13
Merge branch 'release-0.3.13'