Fix a potential crash in AssetManager during cleanup.

            if (id != 0 && id < 256) {

                mPackageMap[id] = 0;

            }

            pg->packages.removeAt(index);

            delete pkg;

            if (pkgCount == 1) {

                LOGV("Delete Package Group %d id=%d packageCount=%d name=%s\n",

                      (int)pgIndex, pg->id, (int)pg->packages.size(),

                      String8(pg->name).string());

                mPackageGroups.removeAt(pgIndex);

            }

                delete pg;

            } else {

                pg->packages.removeAt(index);

                delete pkg;

            }

            return;

        }

    }