Revert "Camera: Handle keys only while in app"

This reverts commit 9b1de2990ef4f64afd8b9a96d51d0d11598eaed5.
Revert "Camera: Cleanup hardware key handling"

This reverts commit d61b5304121ed03b40686e49a17a5b8a53ec18f4.
Revert "Camera: Powerkey shutter (2/2)"

This reverts commit 3efe00b0974074e15d40fc6b6882c7c0e161319c.