Write packages.list when granting permissions.

Some permissions have the side effect of adding GIDs right now,
so we need to flush out packages.list.

Bug: 21874693
Change-Id: Ia4398c9f84cf7f151248f821b3fa2c12bdf91b80
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 06e27fc..243f528 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -1586,6 +1586,11 @@
                 grantRequestedRuntimePermissionsForUser(pkg, someUserId);
             }
         }
+
+        // We could have touched GID membership, so flush out packages.list
+        synchronized (mPackages) {
+            mSettings.writePackageListLPr();
+        }
     }
 
     private void grantRequestedRuntimePermissionsForUser(PackageParser.Package pkg, int userId) {