Migrate endpoint annotation eventTrigger.eventFilters to list of filters

[taeold]

Previously, eventFilter attribute was an object:

eventTrigger: {
  eventType: "an.event",
  eventFilter: {
    resource: "my-storage-bucket",
    appId: "12345",
  }
}

We now prefer eventFilter as a list:

eventTrigger: {
  eventType: "an.event",
  eventFilter: [
  {
    attribute: "resource",
    value: "my-storage-bucket",
  }.
  {
    attribute: "appId",
    value: "12345",
  }.
  ]
}

Most of the change in this PR is in tests. Few other minor changes I've squeezed in here:

1. Added a changelog entry for Add support for more instance sizes and regions #1037
2. Deleted obsolete src/common/manifest.ts file
3. Small refactoring of alerts/crashlytics spec to make this migration easier.

[colerogers]

Seems like we both made a similar set of changes #1047

[taeold]

@colerogers D'oh can't believe I missed that! Do you want to update your PR with some of the other minor changes I've made or use this one instead? I didn't look too closely, but it looks like it's mostly char-by-char the same change.

[colerogers]

@taeold We can just use yours! But I found a small issue when I changed the alerts providers, the attributes should not have been camel cased. If you can just yank all the files from v2/providers/alerts/* in my branch to to this branch, we should be good to go!

[taeold]

@colerogers Nice! Updated the PR.

[colerogers]

Should we add a changelog entry for this PR too?

[taeold]

I chose not to since this change is refactoring non-user facing APIs. Let me know if you disagree.

[inlined]

Why the empty src/common/manifest.ts?

[inlined]

I love the matrix driven tests. Good job deleting so much code!

[taeold]

@inlined It's actually deleted:

https://github.com/firebase/firebase-functions/tree/dl-cf3v2-eventfitlers/src/common

I'm not sure why Github PR displays it as an empty file 🤔