Add tests for verifying the behavior of CWakeupManager

Add tests for verifying the behavior of CWakeupManager

To make sure the modification made to CWakeupManager
would not cause any unexpected side-effect especially
on the observer modules, added tests for checking the
behavioral correctness of each operations.

[==========] Running 10 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 10 tests from DefaultFixture
[ RUN      ] DefaultFixture.SettingValueObserverCalledWhenLanguageChanges
[       OK ] DefaultFixture.SettingValueObserverCalledWhenLanguageChanges (2 ms)
[ RUN      ] DefaultFixture.SettingValueObserverCalledWhenAssistantAdded
[       OK ] DefaultFixture.SettingValueObserverCalledWhenAssistantAdded (2 ms)
[ RUN      ] DefaultFixture.SettingValueObserverCalledWhenAssistantDeleted
[       OK ] DefaultFixture.SettingValueObserverCalledWhenAssistantDeleted (2 ms)
[ RUN      ] DefaultFixture.WakeupEventNotTriggeredWhenInactiveMode
[       OK ] DefaultFixture.WakeupEventNotTriggeredWhenInactiveMode (1 ms)
[ RUN      ] DefaultFixture.WakeupEventTriggeredWhenVoiceKeyGetsPressed
[       OK ] DefaultFixture.WakeupEventTriggeredWhenVoiceKeyGetsPressed (1 ms)
[ RUN      ] DefaultFixture.AudioDataReceivedWhenVoiceKeyGetsPressed
[       OK ] DefaultFixture.AudioDataReceivedWhenVoiceKeyGetsPressed (12 ms)
[ RUN      ] DefaultFixture.FinishAudioDataReceivedWhenStoppedBeforeReleasingWithInterval
[       OK ] DefaultFixture.FinishAudioDataReceivedWhenStoppedBeforeReleasingWithInterval (604 ms)
[ RUN      ] DefaultFixture.FinishAudioDataReceivedWhenStoppedBeforeReleasingWithoutInterval
[       OK ] DefaultFixture.FinishAudioDataReceivedWhenStoppedBeforeReleasingWithoutInterval (303 ms)
[ RUN      ] DefaultFixture.FinishAudioDataReceivedOnResultBeforeReleasingWithInterval
[       OK ] DefaultFixture.FinishAudioDataReceivedOnResultBeforeReleasingWithInterval (607 ms)
[ RUN      ] DefaultFixture.FinishAudioDataReceivedOnResultBeforeReleasingWithoutInterval
[       OK ] DefaultFixture.FinishAudioDataReceivedOnResultBeforeReleasingWithoutInterval (303 ms)
[----------] 10 tests from DefaultFixture (1837 ms total)
[----------] Global test environment tear-down
[==========] 10 tests from 1 test suite ran. (1837 ms total)
[  PASSED  ] 10 tests.

Change-Id: I95054494410f2583874e94cd48277cc205dc1353