Max animation time for idle screen brightness  mode

- Switch animation time cap when switching between idle and interactive
  screen brightness mode.
- Fallback to interactive mode value if no value is specified
- Gate this behind flag

Additionally:
- add tests in DisplayDeviceConfigTest for fallback values for auto brightness light debounce

Bug: 252770716
Test: atest DisplayServiceTests
Test: adb shell setprop persist.sys.com.android.server.display.feature.flags.enable_adaptive_tone_improvements_1 1

Change-Id: Iee8d299f4ae9c2ed9e1b96e539480eebe4a986f7
diff --git a/AconfigFlags.bp b/AconfigFlags.bp
index c35424d..7913ad1 100644
--- a/AconfigFlags.bp
+++ b/AconfigFlags.bp
@@ -34,6 +34,7 @@
     ":sdk_sandbox_flags_lib{.generated_srcjars}",
     ":android.permission.flags-aconfig-java{.generated_srcjars}",
     ":hwui_flags_java_lib{.generated_srcjars}",
+    ":display_flags_lib{.generated_srcjars}",
 ]
 
 filegroup {
@@ -305,3 +306,10 @@
     aconfig_declarations: "hwui_flags",
     defaults: ["framework-minus-apex-aconfig-java-defaults"],
 }
+
+// Display
+java_aconfig_library {
+    name: "display_flags_lib",
+    aconfig_declarations: "display_flags",
+    defaults: ["framework-minus-apex-aconfig-java-defaults"],
+}