PackageUtil: Fix NPE in getPackageInfo method

Added a null check before accessing the file array length to prevent a crash caused by a NullPointerException in cases where the directory is not valid or is inaccessible

Issue: calyxos#2834
Change-Id: I5906ff6b415a766c9cad66220d8ae9ed2290bdb8

packages/PackageInstaller/src/com/android/packageinstaller/PackageUtil.java

@@ -79,7 +79,8 @@ public static PackageInfo getPackageInfo(Context context, File sourceFile, int f
         String filePath = sourceFile.getAbsolutePath();
         if (filePath.endsWith(SPLIT_BASE_APK_END_WITH)) {
             File dir = sourceFile.getParentFile();
-            if (dir.listFiles().length > 1) {
+            File[] files = dir.listFiles();
+            if (files != null && files.length > 1) {
                 // split apks, use file directory to get archive info
                 filePath = dir.getPath();
             }