Gallery2: The settings in the gallery is blank.

The settings' activity is blank.

The settings is added by Google, maybe there is some functions later.
So just take is as annotation.

Change-Id: I2c738def95b2ce08c679f83d9d8e26130b503ada
CRs-Fixed: 745988
Gallery2: Prompt inf does not translate to Chinese.

The string headset_plug does not have Chinese translation.

Add Chinese translation for string headset_plug.

Change-Id: I95d4f9c8836861615963060064a91c4c4e33db54
CRs-Fixed: 744825
Gallery2: Add audio output switcher between headset/speaker

There is no audio output switcher between headset/speaker.

Add the audio output switcher button to menu list in order to
let user use this function.

CRs-Fixed: 650867

Change-Id: I16f5fdc74a76ee55557ba87b0145e51165f0408a