[Gradle, Test] Reset locale to default when changing it for tests

Since `Locale.setDefault` is a global operation it will take effect on
other test causing them to produce unexpectable results.

^KT-38712

libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/ConfigurationsTest.kt

@@ -382,8 +382,17 @@ class ConfigurationsTest : MultiplatformExtensionTest() {
      */
     @Test
     fun `gradle entities should have correct names when default locale is turkish`() {
-        Locale.setDefault(Locale("tr", "TR"))
+        fun withLocale(locale: Locale, code: () -> Unit) {
+            val currentLocal = Locale.getDefault()
+            try {
+                Locale.setDefault(locale)
+                code()
+            } finally {
+                Locale.setDefault(currentLocal)
+            }
+        }
 
+        withLocale(Locale("tr", "TR")) {
             val project = buildProjectWithMPP {
                 kotlin {
                     jvm()
@@ -411,3 +420,4 @@ class ConfigurationsTest : MultiplatformExtensionTest() {
             )
         }
     }
+}