Let OS handle text selection popup

[tthbaltazar]

Fixes #5031.

[connyduck]

What exactly is this doing? I see no difference in the text selection popup.

[tthbaltazar]

Uh. Sorry, this is not the fix.

After a long time of staring into android source code I found the real bug: android hides other apps, and this also affects the actions shows in the text selection popup.

The real solution is to declare that we want to see activities that can handle PROCESS_TEXT actions: https://developer.android.com/training/package-visibility/declaring#intent-filter-signature

This explains why the behavior is so different between apps. I'm pretty sure this is a bug and this should be visible by default to all apps. I guess androidx could fix this by putting this into the manifest of every app.