Update snooze notification icon (white for pre-L, tint for L+)

Also rename all notification pngs to follow the convention
ic_NAME_COLOR_DP.png and all notification drawables as ic_NAME_DP.xml

Bug: 19458148
Change-Id: I7da333e4715d84f5c59dbc8be2c62ef24b3176d8
49 files changed