Android: Fixes #12484: Fix cursor jumps to the beginning of inputs on tap

[personalizedrefrigerator]

Summary

This pull request removes a workaround that broke focus behavior after the upgrade to React Native 0.79. The workaround originally resolved a cursor placement issue in long multi-line TextInputs (see facebook/react-native#29911).

Note: Joplin no longer uses a multiline <TextInput by default for the main editor, so facebook/react-native#29911 should be less likely to impact users. However, if the plain text editor is enabled in settings > general, facebook/react-native#29911 still seems to affect Joplin.

Fixes #12484.

Testing plan

1. Open a note.
2. Open the note editor.
3. Show the search bar.
4. Search for something.
5. Tap the end of the search bar.
6. Verify that the cursor is positioned at the end of the search bar.
7. Tap the end of the note titlebar.
8. Verify that the cursor is positioned at the end of the titlebar.
9. Enable "Use the plain text editor" in settings > note.
10. Open a long note.
11. Open the note editor.
12. Tap on a paragraph.
13. Verify that the cursor was moved to the location of the tap.

[mrjo118]

On some versions of Android 6, the user had to use the plain text editor to get note editing to work. However Android 6 will be desupported in Joplin 3.4 due to the upgrade to rn 0.79. That's definately something to mention in the release notes