composer3: minor fix to dpi documentation 

Change-Id: Ie31cb78f682761d1022592a22867307ab78b5a75
Test: prebuild
diff --git a/graphics/composer/aidl/android/hardware/graphics/composer3/DisplayConfiguration.aidl b/graphics/composer/aidl/android/hardware/graphics/composer3/DisplayConfiguration.aidl
index b0095d2..f4a7c45 100644
--- a/graphics/composer/aidl/android/hardware/graphics/composer3/DisplayConfiguration.aidl
+++ b/graphics/composer/aidl/android/hardware/graphics/composer3/DisplayConfiguration.aidl
@@ -30,7 +30,7 @@
     int height;
 
     /**
-     * Dots per thousand inches.
+     * Dots per inch.
      * If the DPI for a configuration is unavailable or is
      * considered unreliable, the device may set null instead.
      */