Add test for setOverrideFrameRate

- Create test to verify the API call in SurfaceComposerClient
- Create test to verify frame rate override DisplayEventReceiver events
are correctly received
- Add permission AID_ROOT to setOverrideFrameRate

Bug: b/204322816
Test: atest Surfaceflinger_test
Change-Id: I5b1782fcb7fc4896139ad56fcaee61853480f153
diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index 7b86229..c5c0c3f 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -47,6 +47,7 @@
         "ReleaseBufferCallback_test.cpp",
         "ScreenCapture_test.cpp",
         "SetFrameRate_test.cpp",
+        "SetFrameRateOverride_test.cpp",
         "SetGeometry_test.cpp",
         "Stress_test.cpp",
         "SurfaceInterceptor_test.cpp",