SurfaceTexture: use eglWaitSync

This change adds a compile-option to use eglWaitSyncANDROID to ensure that
texturing operations that access the current buffer of a SurfaceTexture do not
occur until the buffer is completely written.  It also moves this
synchronization into a new SurfaceTexture method called doGLFenceWait and
changes SurfaceFlinger's Layer class to use that method rather than performing
its own wait on the fence.

Change-Id: I70afa88086ca7ff49a80e3cd03d423767db7cb88