InCallUI: Validate function return value to avoid NPE

Change-Id: I265860937d9489ef52934be759637a868349a23e
Automatic translation import

Change-Id: I56c76c398bb603c99f6bafc8c219e335696ce573
Automatic translation import

Change-Id: I9140bf4f116d6424c461b8f89c647b246e3b014f
Merge branch 'cm-11.0' into stable/cm-11.0