Add @InspectableProperty annotations to LayoutParams

Change-Id: I69eb71bec8bbf36564e178a3ddf4be9e00e2d531
Fix: 126913705
Test: m framework
diff --git a/core/java/com/android/internal/widget/ViewPager.java b/core/java/com/android/internal/widget/ViewPager.java
index 64bdc6e..f48b56d7 100644
--- a/core/java/com/android/internal/widget/ViewPager.java
+++ b/core/java/com/android/internal/widget/ViewPager.java
@@ -46,6 +46,7 @@
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction;
 import android.view.animation.Interpolator;
+import android.view.inspector.InspectableProperty;
 import android.widget.EdgeEffect;
 import android.widget.Scroller;
 
@@ -2779,6 +2780,9 @@
          * Where to position the view page within the overall ViewPager
          * container; constants are defined in {@link android.view.Gravity}.
          */
+        @InspectableProperty(
+                name = "layout_gravity",
+                valueType = InspectableProperty.ValueType.GRAVITY)
         public int gravity;
 
         /**