install APK from cache directory

AndroidManifest.xml

    <!-- add this permission -->
    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
   
    <!-- add provider -->
    <application ...>
      
        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="${applicationId}.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_provider_paths" />
        </provider>
      
    </application>

file_provider_paths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path
        name="files"
        path="." />
    <cache-path
        name="files"
        path="." />
</paths>

FileExtenstion.kt

fun Context.requestPackageInstall(file: File?) {

    if (file == null) {
        return
    }

    val uri: Uri

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
        uri = FileProvider.getUriForFile(this, "$packageName.provider", file)
    } else {
        val fileName = "temp.apk"
        val fos = openFileOutput(fileName, MODE_WORLD_READABLE or MODE_WORLD_WRITEABLE)
        val tempFile = File(filesDir, fileName)
        uri = Uri.fromFile(tempFile)
        try {
            fos.write(file.readBytes())
        } catch (e: Exception) {
            Log.e("File_Extension", e.message)
        } finally {
            fos.close()
        }
    }

    val intent = Intent(Intent.ACTION_INSTALL_PACKAGE).apply {
        setDataAndType(uri, "application/vnd.android.package-archive")
        addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
    }
    startActivity(intent)

}