Describe the bug

Due to a recent change, the enter key stopped working in captions on Android. It used to add new lines within the caption, but now the newline is immediately removed.

To Reproduce

Steps to reproduce the behavior:

1. Create a caption
2. Press "Enter"
3. Observe that the cursor has not moved to a new line or a new block

Expected behavior

It is unclear what the expected behavior should be. Previously, we were allowing the addition of new lines in captions. @hypest has noted, however, that this is inconsistent with the way that the "Enter" key is handled elsewhere (i.e., paragraph blocks) on mobile. For that reason, he has suggested that we may also want to have the enter key move to a new paragraph block from within captions. It should be noted, however, that this would be a change from web, which has the Enter key create new lines within captions but has the enter key create a new paragraph block elsewhere. What do you think is the best way to proceed here @iamthomasbishop ?

Smartphone

Pixel, Android 10, gutenberg-mobile 1.18.0