JavaScript Controller TextInput keep their own state and value for the
TextInput. This means that the value in Java

"This is my word"

can be different from the value in JavaScript, in the case of the
relevant example we delete spaces from sentence like below

"Thisismyword"

The two strings have different length, this causes several problems, an
example is

setSpan(5 ... 5) ends beyond length 4
facebook#29070 (comment)

where we change in JavaScript the TextInput value, but then a
setSelection or other operations are triggered in Java with the old
parameters.

Ideally would be great keeping the same state between Java and
JavaScript, but the current solution is checking and handling this
scenarios

Pull Request facebook#29070 solves
issue facebook#11068 by calling
setText(string)

https://github.com/fabriziobertoglio1987/react-native/blob/a66718881611eb687035ff458f7f13befd26f0a3/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java#L509-L511

but using setText() causes further problems:

1) After setText we need to call setSelection, to position the cursor at
   the previous state. setText will erase the previous cursor position
https://github.com/fabriziobertoglio1987/react-native/blob/a66718881611eb687035ff458f7f13befd26f0a3/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java#L511

2) calling setSelection after setText causes issues with controlled TextInput. The TextInput is keeping its own internal TextInput value state, which is different from the Java version and has different length.

facebook#29070 (comment)

This causes erors like below, when Java runs operations like
setSelection after setText, as the text in Java is not the JavaScript
version of the Text.

setSpan(5 ... 5) ends beyond length 4

A solution for this is keeping track of the reactTextUpdate.length sent
from JavaScript and saving it as instance variable mMaximumTextLength

3) JavaScript functionality can be included in the library or in
   ReactNative Application to build fully controller TextInputs.

   An example is the one included in this diff, where I use
   onSelectionChange, selection and onChangeText to set from JavaScript
   the position of the cursor, avoiding to set the cursor in a position
   higher then text.length

   The same functionality could be later included in TextInput.js

fixes issue caused by setPosition in a new position higher then
text.length();

setSpan(5 ... 5) ends beyond length 4
facebook#29070 (comment)

mMaximumTextLength was added to fix the error described in facebook#29070 (comment) :
```
setSpan(5 ... 5) ends beyond length 4
```
A similar fix was merged in master with commit facebook@de44184, I reverted this changes as the existing solution seems to fix this error.

code review facebook#29070 (comment)