bump warn agp version from 7.3 to 8.3 (#166555)

Bumping the warn agp version from 7.3 (sept 2022) to 8.3 (feb 2024).
This is because we will likely need to depend on apis available in the
newer versions of AGP as part of our work to migrate to the
public/stable agp api. Warning will not break customers but starts the
clock on being able to bump error version.

I would have also bumped the error version but want to get this in
before the 3.32 cut next monday and adding errors can cause review
delay.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [ ] I listed at least one issue that this PR fixes in the description
above.
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Jackson Gardner <jacksongardner@google.com>

packages/flutter_tools/gradle/src/main/kotlin/DependencyVersionChecker.kt

@@ -91,7 +91,7 @@ object DependencyVersionChecker {
 
     @VisibleForTesting internal val errorJavaVersion: JavaVersion = JavaVersion.VERSION_1_1
 
-    @VisibleForTesting internal val warnAGPVersion: AndroidPluginVersion = AndroidPluginVersion(7, 3, 1)
+    @VisibleForTesting internal val warnAGPVersion: AndroidPluginVersion = AndroidPluginVersion(8, 3, 0)
 
     @VisibleForTesting internal val errorAGPVersion: AndroidPluginVersion = AndroidPluginVersion(7, 0, 0)
 

packages/flutter_tools/gradle/src/test/kotlin/DependencyVersionCheckerTest.kt

@@ -53,7 +53,7 @@ private const val FAKE_PROJECT_ROOT_DIR = "/fake/root/dir"
 // are updated in DependencyVersionChecker.kt
 private const val SUPPORTED_GRADLE_VERSION: String = "7.4.2"
 private val SUPPORTED_JAVA_VERSION: JavaVersion = JavaVersion.VERSION_11
-private val SUPPORTED_AGP_VERSION: AndroidPluginVersion = AndroidPluginVersion(7, 3, 1)
+private val SUPPORTED_AGP_VERSION: AndroidPluginVersion = AndroidPluginVersion(8, 3, 0)
 private const val SUPPORTED_KGP_VERSION: String = "1.8.10"
 private val SUPPORTED_SDK_VERSION: MinSdkVersion = MinSdkVersion("release", 30)
 
@@ -82,7 +82,7 @@ class DependencyVersionCheckerTest {
 
     @Test
     fun `AGP version in warn range results in warning logs`() {
-        val exampleWarnAgpVersion = AndroidPluginVersion(7, 1, 0)
+        val exampleWarnAgpVersion = AndroidPluginVersion(8, 2, 0)
         val mockProject = MockProjectFactory.createMockProjectWithSpecifiedDependencyVersions(agpVersion = exampleWarnAgpVersion)
 
         val mockExtraPropertiesExtension = mockProject.extra