Noticed during internal call for testing (comment here pbMoDN-1oy-p2#comment-2763).

Expected behavior

When adding multiple images to a gallery block from Free Photo Library (could possibly happen also with other sources), I would expect those images to be uploaded into the gallery block

Actual behavior

When adding multiple images to a gallery block from Free Photo Library (could possibly happen also with other sources), it has been reported sometimes the app goes ANR.

Steps to reproduce the behavior

There is a suspect it can happen when the post becomes too big, but note I was not able currently to reproduce it. (cc @AmandaRiu )

• In GB add a gallery block
• Add images from Free Photo Library
• App could go in ANR

Tested on [Pixel 3 Emu], Android [API30], WPAndroid [#13216 CI Build]