Fix build.

Change-Id: I97e357aa20c9ba91f20f77d53fc4dca1fd3aa598
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index e4499797..a70a219 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -109,6 +109,7 @@
         }
     }
 
+    /** @hide */
     public void setFrontActivityScreenCompatMode(int mode) {
         try {
             ActivityManagerNative.getDefault().setFrontActivityScreenCompatMode(mode);
@@ -117,6 +118,7 @@
         }
     }
 
+    /** @hide */
     public int getPackageScreenCompatMode(String packageName) {
         try {
             return ActivityManagerNative.getDefault().getPackageScreenCompatMode(packageName);
@@ -126,6 +128,7 @@
         }
     }
 
+    /** @hide */
     public void setPackageScreenCompatMode(String packageName, int mode) {
         try {
             ActivityManagerNative.getDefault().setPackageScreenCompatMode(packageName, mode);