Merge "[GraphicsEnvironment] Avoid null access." am: 393215e245

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1530839

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I5af8bb8a0d5f1b6d4bb9b26e8e049720135b5109

core/java/android/os/GraphicsEnvironment.java

@@ -249,6 +249,7 @@ public class GraphicsEnvironment {
         }
         if (appInfo == null) {
             Log.w(TAG, "Debug layer app '" + packageName + "' not installed");
+            return "";
         }
 
         final String abi = chooseAbi(appInfo);