Terminate EGL display after use

Terminate EGL display after use

Previously function getDefaultEglConfigList destroyed native
display but did not terminate the EGL display. It may happen
that next create call will allocate native display at same
address as previous and as per spec multiple calls made to
eglGetPlatformDisplayEXT with the same <platform> and
<native_display> will return the same EGLDisplay handle. But
returned EGLDisplay will have references to stale data.

To fix this destroy the EGL Display along with native display.

Affects: CTS-Configs.*

Components: OpenGL and Framework

VK-GL-CTS Issue: 1426

Change-Id: I8e4c7d693d26bd9be6d7f892d0b5162d9b2b245c