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
diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index b1d45f39..32bf66a 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -35,6 +35,7 @@
     srcs: [
         ":libsurfaceflinger_sources",
         "libsurfaceflinger_unittest_main.cpp",
+        "AllowedDisplayConfigsTest.cpp",
         "CompositionTest.cpp",
         "DisplayIdentificationTest.cpp",
         "DisplayTransactionTest.cpp",