## Description
This PR simplifies one external link in a commented section of the Android manifest template.
## Related Issue
Fixes https://github.com/flutter/flutter/issues/144249
## Tests
Documentation only PR.
Re-sets two jvmargs that were getting cleared because we set a value for `-Xmx`. Could help with https://github.com/flutter/flutter/issues/142957. Copied from comment here https://github.com/flutter/flutter/issues/142957:
>Two random things I ran into while looking into this that might help:
>
>1. Gradle has defaults for a couple of the jvmargs, and setting any one of them clears those defaults for the others (bug here https://github.com/gradle/gradle/issues/19750). This can cause the "Gradle daemon to consume more and more native memory until it crashes", though the bug typically has a different associated error. It seems worth it to re-set those defaults.
>2. There is a property we can set that will give us a heap dump on OOM ([-XX:HeapDumpOnOutOfMemoryError](https://docs.oracle.com/javase/8/docs/technotes/guides/troubleshoot/clopts001.html))
Mostly just a find and replace from `find . -name gradle.properties -exec sed -i '' 's/\-Xmx4G/-Xmx4G\ \-XX:MaxMetaspaceSize=2G\ \-XX:+HeapDumpOnOutOfMemoryError/g' {} \;`, with the templates and the one test that writes from a string replaced by hand. I didn't set a value for `MaxMetaspaceSize` in the template files because I want to make sure this value doesn't cause problems in ci first (changes to the templates are essentially un-revertable for those who `flutter create` while the changes exist).
This PR updates almost* all Gradle buildscripts in the Flutter repo the `example` and `dev` (in particular, in `dev/integration_tests` and in `dev/benchmarks`) directories to apply Flutter's Gradle plugins using the declarative `plugins {}` block.
*almost, because:
- add-to-app (aka hybrid) apps are not migrated (related https://github.com/flutter/flutter/issues/138756)
- apps that purposefully use build files to ensure backward compatibility (e.g. [`gradle_deprecated_settings`](https://github.com/flutter/flutter/tree/3.16.0/dev/integration_tests/gradle_deprecated_settings))
