RNFetchBlobFS.writeFile(): improve IO error handling

convert to new react native config format

Fix android Flag issue in android 9 and open file in Download directory in Android also

Hash - changed to chunk size instead of reading entire file

require cycle

Solve the conflict between FileProvider and other libraries

Androidx upgrade

fix cocoa pod 0.60.0 for rn-fetch-blob

Remove unused AsyncStorage import (Deprecated in RN 0.59)

See: https://developer.android.com/reference/java/nio/charset/Charset.html#defaultCharset()

> Android note: The Android platform default is always UTF-8.

See: https://developer.android.com/reference/java/nio/charset/Charset.html#defaultCharset()

> Android note: The Android platform default is always UTF-8.

These constants were never actually implemented.

This is caused by an error on Android 9: 'Error: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?'

Not working in iPhone due to presence of charset utf-8

This fixed the warning for "require cycle" on newer React-Versions

This reverts commit d69c72bb3f, reversing
changes made to c95ef1c199.

Add flow type definitions

update android build config for newer react-native versions