Upgrade to RN v0.67

[gnprice]

The next round after #5231. (Which at present we haven't done yet, but this gives us a place to leave information about this version. edit: now done.) Blog post here:
https://reactnative.dev/blog/2022/01/19/version-067
and more-detailed changelog:
https://github.com/facebook/react-native/blob/main/CHANGELOG.md#v0670

[gnprice]

This version looks like it should be relatively smooth, with fewer changes than many previous releases. I guess that fits with coming out just 3 months after the previous release.

• There's not much highlighted in the blog post, and nothing that should affect us.
  • Well, it does mention "Bump Gradle version to 7.2". The only thing that definitely means is that they bumped the version in the template app; but it's possible they also introduced some incompatibility with Gradle 6.9, which we're on. If so, we'll need to upgrade Gradle first: that's Upgrade to Gradle 7 and AGP 7 #5377.
• I just read through the more-detailed changelog, and nothing stands out as a likely speed-bump.