Add missing case for apk file

Signed-off-by: huynguyennovem <huynguyennovem@gmail.com>

Author: huynguyennovem

android/app/src/main/AndroidManifest.xml

@@ -6,6 +6,7 @@
 
     <!--flutter_downloader-->
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="28" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />  <!--Install .apk files-->
 
     <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>