TextInput controlled selection broken on both ios and android.

This issue is a continuation of the discussion:
https://github.com/facebook/react-native/commit/dff490d140010913d3209a2f3e987914b9c4eee4#commitcomment-39332764
The link to the sample project that demonstrates the issues:
https://github.com/Ginger-Labs/Input-bug

Description

Controlled selection seems to be broken on both ios and android, to demonstrate the issues I created a sample project (find the link above).

React Native version:

System:
OS: macOS 10.15.4
CPU: (8) x64 Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz
Memory: 1.55 GB / 16.00 GB
Shell: 5.7.1 - /bin/zsh
Binaries:
Node: 10.14.2 - /usr/local/bin/node
Yarn: 1.13.0 - /usr/local/bin/yarn
npm: 6.14.5 - ~/.npm-global/bin/npm
Watchman: 4.9.0 - /usr/local/bin/watchman
SDKs:
iOS SDK:
Platforms: iOS 13.5, DriverKit 19.0, macOS 10.15, tvOS 13.4, watchOS 6.2
Android SDK:
API Levels: 23, 24, 25, 26, 27, 28, 29
Build Tools: 26.0.3, 28.0.3, 29.0.0, 30.0.0
System Images: android-28 | Google APIs Intel x86 Atom, android-28 | Google Play Intel x86 Atom, android-29 | Google APIs Intel x86 Atom, android-29 | Google Play Intel x86 Atom_64
Android NDK: 21.1.6352462
IDEs:
Android Studio: 3.6 AI-192.7142.36.36.6392135
Xcode: 11.5/11E608c - /usr/bin/xcodebuild
npmPackages:
react: ~16.9.0 => 16.9.0
react-native: ~0.62.2 => 0.62.2
npmGlobalPackages:
create-react-native-app: 3.4.0
react-native-app-id: 0.0.5
react-native-cli: 2.0.1

Steps To Reproduce

The reproduction steps are in the sample project's ReadMe file.
For simplicity purposes, I will post them here as well:

SIM - iPhone 11 (13.4.1):

1. Click on the "Click Me" Button, set the cursor in the middle, add some text, click on the button again: Notice the text is set to needed one but the selection is not 10
2. Input text: "Hello world", move cursor in between words, click on "@":
   Expected: "Hello @Mihailworld" with the cursor at 13
   Actual: "Hello @Mihailworld" with the cursor at the end of the whole string.

SIM - nexus 6P API28

1. Add text, click on enter (new line).
   Expected: The text stays and a new line is created with "-" in front.
   Actual: The first line becomes empty and the second line "-".
2. Press enter twice and you will get a:
   Exception in native call java.lang.IndexOutOfBoundsException: setSpan (6 ... 6) ends beyond length 3
3. Press "@" twice and observe the same bug above.

Expected Results

I expect the TextInput to work as intended (unless I am missing something conceptual).

Snack, code example, screenshot, or link to a repository:

https://github.com/Ginger-Labs/Input-bug

Beginne mit den Reproduktionsschritten in der README des verknüpften Input-bug-Beispielprojekts und reproduziere das Verhalten der kontrollierten TextInput-Auswahl in den aufgeführten iOS- und Android-Umgebungen. Vergleiche die beobachteten Ergebnisse für Cursor, Zeilenumbruch und IndexOutOfBoundsException mit den erwarteten Ergebnissen; die Arbeit ist abgeschlossen, wenn sich die kontrollierte Auswahl auf beiden Plattformen korrekt verhält.