chore(deps): bump junit in /tutorials/kotlin/Polygons (#350)

Bumps [junit](https://github.com/junit-team/junit4) from 4.13 to 4.13.1.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/main/doc/ReleaseNotes4.13.1.md)
- [Commits](junit-team/junit4@r4.13...r4.13.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

tutorials/kotlin/Polygons/app/build.gradle

@@ -42,7 +42,7 @@ dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'androidx.appcompat:appcompat:1.2.0'
     implementation 'com.google.android.gms:play-services-maps:17.0.0'
-    testImplementation 'junit:junit:4.13'
+    testImplementation 'junit:junit:4.13.1'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
     implementation "androidx.core:core-ktx:1.3.2"