Reset speakerphone at beginning and end of calls

Always call AudioManager#setSpeakerphoneOn(false) at the beginning and
end of calls.

Bug: 69305994
Bug: 70338906
Test: unit
Change-Id: Ifcd887ca7bdeab8cff8a2773a306548142979238
Merged-In: Ifcd887ca7bdeab8cff8a2773a306548142979238
(cherry picked from commit 0814db7b)