Merge in class filtering solution from issue 336

[emanguy]

Summary

Adds in filtering for contents of attributes as proposed in #336 (thanks for the sample code @ravishivt !)

Fixes #336

Test Plan

Tested by adding into storyshots tests for my company, but additional automated testing would be great. Please advise on what I should do for that. Sample from one of the tests:

Update: the example app snapshot test verifies this functionality.

What's required for testing (prerequisites)?

What are the steps to reproduce (after prerequisites)?

Compatibility

OS	Implemented
iOS	✅
Android	✅

(assuming the other serializer code works, this should too)

Checklist

• I have tested this on a device and a simulator
• I added the documentation in README.md
• I mentioned this change in CHANGELOG.md
• I updated the typed files (TS and Flow)
• I added a sample use of the API in the example project (example/App.js)

[emanguy]

The test above failed because the no NG attributes serializer removed the auto-added angular classes as expected. Don't know if that helps the case for the fact that this works.

[ahnpnl]

• I think you can update snapshot of the failed test.
• Is it possible to remove ng-star-inserted in this PR too ?

[emanguy]

How do I update the snapshot? I didn't see anything referencing the snapshots in the npm scripts

[ahnpnl]

Hi, you can do this:

• cd examples
• yarn test -u

Indeed there is no update snapshot script but you just need to use jest cli option.

[emanguy]

Ah, I didn't realize there was a separate NPM project in the example directory. I've made the changes you requested.

[emanguy]

Sorry this has gotten stale. I'll get around to making the changes this weekend.

[emanguy]

Alright! Changes are made. The regexes are now more targeted at things following those prefixes.

[wtho]

Awesome! Looks great! Thanks so much!
Can you add an entry to CHANGELOG.md so we can merge it directly?

@ahnpnl please have another look and we can get this merged.

[ahnpnl]

LGTM, only needs to resolve the conflict and add CHANGELOG.md 👍

Probably this also needs to be ivy compatible, but that will be for another PR imo.

[intellix]

How about also this which creeped in since updating to 8.1.3 with ivy support:

  __ngContext__={[Function LRootView]}

Also, you said ivy compatible can come after but that support is already in master so... required?

[ahnpnl]

The current snapshot serializer in 8.1.3 is already compatible with ivy. This PR is only an enhancement to get rid of unwanted attributes :)

[emanguy]

Changelog is updated, I'm hoping you intended for me to put it in the 8.1.3 changes!

Merge conflict is also resolved.

[wtho]

No, 8.1.3 is already released. I will fix in on the 8.2 release though.
Thanks a lot!

[wtho]

Released in v8.2.0.