fix(ios): improve image rendering performance on main thread

[ruifanyuan]

Before submitting a new pull request, please make sure:

• Test cases have been added/updated/passed for the code you will submit.
• Documentation has added or updated.
• Commit message is following the Convention Commit guideline with maximum 72 characters.
• Squash the repeat code commits, short patches are welcome.

[hippy-service]

Hi, @ruifanyuan. Thanks for your PR! 👏

🏷️ You can leave a comment in this PR with #help tag when you need help (e.g. some status checks run failed due to internal issue), admin team members will help asap.

[hippy-service]

Pay attention 🛎️ !!
There has been no activity on this PR for 2 months, so I will label it stalled.
It will be automatically closed in 30 days if no more activity. Feel free to leave a comment if you have any questions.

[hippy-service]

Sorry, closing this PR because it has stalled for over 4 months.
Feel free to reopen if this PR is still relevant, or to ping the collaborator if you have any questions.