PlaybackOverlayFragment: allow fadeOut when fadeEnabled is false

PIP needs to setFadingEnabled(false) and hide the controls.  But when
calling setFadingEnabled(false),  the control will be faded in,  then
fadeOut() is ignored.

Bug 28667137

Change-Id: Iee6febc9491d0ca0b1bb0431ddcd40aca889357f
2 files changed