Add configurable strength values for Reduce Bright Colors

Test: atest FrameworkServicesTests:ReduceBrightColorsTintControllerTest,
atest FrameworksServicesTests:ColorDisplayServiceTest

 Bug: b/179805222

Change-Id: I70bfedd9d2226abac2a2cb6952ffb835ea8891d5

core/java/android/hardware/display/ColorDisplayManager.java

@@ -536,6 +536,26 @@ public final class ColorDisplayManager {
         return context.getResources().getBoolean(R.bool.config_reduceBrightColorsAvailable);
     }
 
+    /**
+     * Returns the minimum allowed brightness reduction strength in percentage when activated.
+     *
+     * @hide
+     */
+    public static int getMinimumReduceBrightColorsStrength(Context context) {
+        return context.getResources()
+                .getInteger(R.integer.config_reduceBrightColorsStrengthMin);
+    }
+
+    /**
+     * Returns the maximum allowed brightness reduction strength in percentage when activated.
+     *
+     * @hide
+     */
+    public static int getMaximumReduceBrightColorsStrength(Context context) {
+        return context.getResources()
+                .getInteger(R.integer.config_reduceBrightColorsStrengthMax);
+    }
+
     /**
      * Check if the color transforms are color accelerated. Some transforms are experimental only
      * on non-accelerated platforms due to the performance implications.