SurfaceFlinger: add unit test for AllowedDisplayConfigs

Add a new unit test for AllowedDisplayConfigs class.

Fixes: 124934007
Test: adb shell /data/nativetest64/libsurfaceflinger_unittest/libsurfaceflinger_unittest
Change-Id: I0b37ed969bc9ede3487fb6baaafd751b012ed4df
2 files changed