Check wide-color support before adding extensions

Don't want applications seeing the wide-color EGL extensions
if the device or display cannot support wide-color.
Bug: 63170158
Test: adb shell /data/nativetest/test-opengl-gl2_basic/test-opengl-gl2_basic
Verify that EGL_EXT_gl_colorspace_scrgb, EGL_EXT_gl_colorspace_scrgb_linear,
EGL_EXT_gl_colorspace_display_p3_linear and EGL_EXT_gl_colorspace_display_p3
are not present on devices that do not support wide-color, e.g. Nexus 6P

Change-Id: I46a26a67f2d6da9c5aad50d884ef02a62ccb6945
(cherry picked from commit e5d6f994)