Upgrade to gradle 7.1.1

[oguzkocer]

This PR is part of Gradle 7 upgrade for react-native libraries for Gutenberg. There are 13 libraries that are upgraded to Gradle 7 and they follow the general outline below:

• Gradle version upgraded to 7.1.1 with ./gradlew wrapper --gradle-version=7.1.1 --distribution-type=all command. There were a few cases where gradlew file was missing or wasn't executable, and these were also addressed as part of this change.
• Gradle plugins are moved to settings.gradle.kts file by utilizing Plugin DSL. Since only one settings file is executed per build, except for composite builds, this allows us to change the plugin versions from the root project. For example, all these projects are added to react-native-bridge as a project dependency and now that react-native-bridge itself uses Plugin DSL, it can set the Android Gradle plugin & Kotlin plugin version without making changes to these libraries. This should make our lives easier when it comes to upgrading to new versions of Android Gradle plugin.
• Simplifies android extension by removing the fancy minSdk, targetSdk etc setting. If these need to be updated I think they should be done directly as a PR and the fancy code is just making things harder to follow. It's also perfectly fine for a library to be on a lower version if it works fine with it. I think this setting is much more important for applications.
• Updates repositories & dependencies sections of the build file. I am still not super happy with this one, but it'll need to be improved again at a later time, possibly with the new Gradle 7 dependency management features. Most of them are exactly the same, with a few exceptions where it was necessary.
• Updates or adds gradle.properties. I went for a simple version which should work pretty much all the time.
• Adds maven-publish plugin and sets up the publishing block. This allows Jitpack to publish the artifacts and with this update we are actually only one step away from publishing them to S3 🤷
• Either removes jitpack.yml where it's not necessary, or simplifies it greatly by only including what's necessary - such as switching to a different directory because Jitpack can't find the project.

There might be some minor changes for a few projects, but hopefully they'll be self-explanatory. Also the first few PRs I opened may be a little different, but it seems to work and I think we can live with that inconsistency. There is just too many PRs to keep everything straight in my head :(

To test

These changes can be tested as part of the gutenberg-mobile PR or WordPress-Android PR which is updated to use the bundle generated with these changes. Having said that, I think it's best to leave the testing step to the gutenberg PR review since even if we merge these PRs in, it won't impact anything until we update the package.json file that adds these libraries. So, worst case scenario, we just open a follow up PR to fix any issues we find during testing. It's up to the reviewer to decide how to go about testing.

Follow up

Once these PRs are merged in, we'll create a new tag for each library and update the package.json file again.

[mokagio]

Same considerations as my first review in this Upgrade to Gradle 7.1.1 series of PR. 👍

• CI in the Gutenberg PR that introduces these changes is green.
• I verified the Gutenberg PR uses the latest commit in this branch.
• CI in the gutenberg-mobile PR is red, but it's due to an npm issue (cd() never called!) which I don't think relates to these changes.