Fix bug #8051633 Recent Apps thumbnails in RTL mode (Arabic / Hebrew / Farsi) should be aligned

Basically RelativeLayout was broken in a very stubtle way.

RelativeLayout needs in onMeasure() to have a width in RTL mode when "myWidth=-1" (meaning "not
defined") so that the rest of the onMeasure() computation can be done (children positioning and
width computation).

As there is no way to get its width apart from running the code, in RTL mode we set its width
arbitrary to the screen width for doing the width computation and children positoning.

Then, as a last pass, we will update and fix the children position (no need to do anything with
the computed width because it is correctly computed  already).

Change-Id: I426af3327160e751ef63ed3845aad5bab6dad661