Add Constant for Notification volume preference

Bug: 332699338
Test: Local Build and test
Change-Id: I64833a950a3cff8d1676b19f595a9d3fd5d3f795
1 file changed
tree: e5966671a87cc6ba0f18b7e32996e2976cfb6f44
  1. stats/
  2. OWNERS