Fix bug #11252410 Recents items stuck behind hammerhead navigation panel in landscape

Right padding was wrong for the LinearLayout with id/recents_linear_layout. Its value
was first correctly set by the fitSystemWindows(Rect insets) call but then was reset
to "0" during padding resolution.

Thus make sure that the initial values for user padding left/righ are also set to the
ones coming from the computed ones.

Change-Id: I60390ff7a24286a8f7214eaff8606cb76268ee90