Check if bp.perm is null before resolving it

Test: Built
Change-Id: I757a28cb6d403267914f5c63f9b4e2cf0cdb079e
diff --git a/services/core/java/com/android/server/pm/permission/PermissionManagerService.java b/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
index 5fa667a..b788935 100644
--- a/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
+++ b/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
@@ -2122,7 +2122,8 @@
                 // Only system declares background permissions, hence mapping does never change.
                 mBackgroundPermissions = new ArrayMap<>();
                 for (BasePermission bp : mSettings.getAllPermissionsLocked()) {
-                    if (bp.perm.info != null && bp.perm.info.backgroundPermission != null) {
+                    if (bp.perm != null && bp.perm.info != null
+                            && bp.perm.info.backgroundPermission != null) {
                         String fgPerm = bp.name;
                         String bgPerm = bp.perm.info.backgroundPermission;