Add the duration type for call time in call log

- use a config to control whether need to display call duration
  type in call log.

Conflicts:
	res/values/config.xml
	src/com/android/dialer/CallDetailActivity.java
	src/com/android/dialer/PhoneCallDetails.java
	src/com/android/dialer/calllog/CallLogAdapter.java
	tests/src/com/android/dialer/PhoneCallDetailsHelperTest.java

Change-Id: I8346aa8006dc48c541a859152cdb7097dfd6f5fe