libhwui: make setSurface asynchronous

On the critical path of the cold launch of applications
the main thread of the started application tells the RenderThread
to create a surface. This process is synchronous and blocks
the main thread of the application until the creation
of the EGLContext is complete.
As a consequence the launch time of the application is delayed
by time spent allocating the EGL Context in the RenderThread.

With this optimization the launch time of any application
is improved (for example settings by 20 to 40 ms).

Change-Id: Ibf47aaa0abb8dedf7aa00693073db3785d9d6b08
Signed-off-by: Thomas Buhot <thomas.buhot@intel.com>
Signed-off-by: Zhiquan Liu <zhiquan.liu@intel.com>