[google_maps_flutter_android] Loop over enum values in toMapColorScheme tests

Replaces three per-value tests with one loop over
PlatformMapColorScheme.values() so a new enum value forces a
compile-time failure in the test when it grows.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: snaeji

packages/google_maps_flutter/google_maps_flutter_android/android/src/test/java/io/flutter/plugins/googlemaps/ConvertTest.java

@@ -522,24 +522,16 @@ public void interpretMapConfiguration_handlesStyle() {
   }
 
   @Test
-  public void toMapColorScheme_light() {
-    Assert.assertEquals(
-        com.google.android.gms.maps.model.MapColorScheme.LIGHT,
-        Convert.toMapColorScheme(PlatformMapColorScheme.LIGHT));
-  }
-
-  @Test
-  public void toMapColorScheme_dark() {
-    Assert.assertEquals(
-        com.google.android.gms.maps.model.MapColorScheme.DARK,
-        Convert.toMapColorScheme(PlatformMapColorScheme.DARK));
-  }
-
-  @Test
-  public void toMapColorScheme_followSystem() {
-    Assert.assertEquals(
-        com.google.android.gms.maps.model.MapColorScheme.FOLLOW_SYSTEM,
-        Convert.toMapColorScheme(PlatformMapColorScheme.FOLLOW_SYSTEM));
+  public void toMapColorScheme_mapsAllPlatformValues() {
+    for (PlatformMapColorScheme value : PlatformMapColorScheme.values()) {
+      final int expected =
+          switch (value) {
+            case LIGHT -> com.google.android.gms.maps.model.MapColorScheme.LIGHT;
+            case DARK -> com.google.android.gms.maps.model.MapColorScheme.DARK;
+            case FOLLOW_SYSTEM -> com.google.android.gms.maps.model.MapColorScheme.FOLLOW_SYSTEM;
+          };
+      Assert.assertEquals(expected, Convert.toMapColorScheme(value));
+    }
   }
 
   @Test