GlobalActions: Fix possible race condition when showing dialog.

Depending on the presence of a previous dialog, the newly generated one
gets either immediately displayed (no old dialog) or shortly delayed
(after dismissal of the existing one).
If a new show event happens (by rapid fire of the power key, for instance,
using a keyboard with fast-repeating events) during that delay, a new
dialog will be immediately displayed, and when the delayed show triggers
it'll conflict with it (and bring everything down).

This moves the creation of the new Dialog object to _before_ showing
it (delayed or not), instead of the show method itself, to ensure the
object isn't clobbered by competing/sequential calls to handleShow()

Change-Id: Ie4d9a8507ebaf59da31869c38b98c3c98a74468e
GLSurfaceView: add property to default to RGB565

Some legacy devices (like the Xoom) are not capable of handling
RGB888 surfaces, which is now the default. This results in some
OpenGL apps crashing with "No config chosen" errors.

Set ro.opengles.surface.rgb565=true to go back to the old default
of RGB565 surfaces.

Credit to dreamcwli for the original patch.

Change-Id: I5ad9aa8e98eb6fd554b01022439141fe4a55bd70