Camera2: added enhanced scene mode menu

Based on CM

Change-Id: Id10da1b5aec9f61dfe3ef0ebdc4e5f0a180af66e
Camera2: added slow shutter support

For N1

Change-Id: Ice6dd2219054cb02a3191ae3484c44824fc6bee5
merge changes from Omni 4.4 into local branch