Close notification panel when swiping away the last clearable
notification.

Change-Id: I4e5114f66e799a7c80e18b38abce5678da460846
Hide navigation ring if no targets are configured.

Change-Id: Ieca5c700f628e9c990483999367aa48d153fd6a5
Derp fix.

Change-Id: I124eb9e6b74556c6ff4ddb1e5335a758dc9250bf