Handle headset plugged event

[lukeweber]

From:

https://android.googlesource.com/platform/packages/apps/Phone/+/5bcbca1162b1b462d15ebb4a5b2859a076d382e2/src/com/android/phone/PhoneApp.java

intentFilter.addAction(Intent.ACTION_HEADSET_PLUG);

mIsHeadsetPlugged = (intent.getIntExtra("state", 0) == 1);

if (!isHeadsetPlugged()) {
// if the state is "not connected", restore the speaker state.
PhoneUtils.restoreSpeakerMode(getApplicationContext());
} else {
// if the state is "connected", force the speaker off without
// storing the state.
PhoneUtils.turnOnSpeaker(getApplicationContext(), false, false);
}

[jreyes]

Fixed on issue 60