Fix 'Generic.kl' file has no 'ZOOM_IN' and 'ZOOM_OUT' mapping

'KEYCODE_ZOOM_IN' and 'KEYCODE_ZOOM_OUT' are defined in 'keycodes.h' and 'keyEvent.java', but not mapped in 'Generic.kl'. I think this is used by the camera to adjust the focus and it should be sent to the camera.

Change-Id: Ib5057ca2151de7a91bfec7f646ad9f491789cc0c
Signed-off-by: zhangzhihao7 <zhangzhihao7@xiaomi.corp-partner.google.com>