Settings: add a new developer menu entry to show hdr/sdr ratio overlay.

- The hdr/sdr ratio overlay will be shown on screen if the option is
  selected from the developer option.
- This option is hidden on non-HDR-supported devices.
- Add flags: com.android.settings.flags.development_hdr_sdr_ratio

Test: enable show hdr/sdr ratio from developer menu; com.android.settings.development.ShowHdrSdrRatioPreferenceControllerTest
Bug: 291863102
Change-Id: Idd72f95c67c95cd8127f9b94e031b3d87b18e307
diff --git a/aconfig/Android.bp b/aconfig/Android.bp
index 78fba34..5c6c8c3 100644
--- a/aconfig/Android.bp
+++ b/aconfig/Android.bp
@@ -8,6 +8,7 @@
     srcs: [
         "settings_accessibility_flag_declarations.aconfig",
         "settings_connecteddevice_flag_declarations.aconfig",
+        "settings_development_flag_declarations.aconfig",
         "settings_globalintl_flag_declarations.aconfig",
         "settings_experience_flag_declarations.aconfig",
         "settings_onboarding_experience_flag_declarations.aconfig",