StatusBarView: Ensure to not overload in/out animations

- Post animate call in main thread, thanks @David96
- Handle animation checking current view visibility

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Signed-off-by: David L.-W. <xD_e-mail@gmx.de>
StatusBarView: Avoid unnecessary calls to mHandler.post()

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Signed-off-by: David L.-W. <xD_e-mail@gmx.de>