Update the size of test color box in screenshot tests for MultiSlotLayout

Bug: 294180819
Test: Updated existing screenshots
Change-Id: I4eac4417275e94371ded543c583e6e7c28db1f2a
diff --git a/wear/protolayout/protolayout-material/src/androidTest/java/androidx/wear/protolayout/material/layouts/TestCasesGenerator.java b/wear/protolayout/protolayout-material/src/androidTest/java/androidx/wear/protolayout/material/layouts/TestCasesGenerator.java
index 02bd273..6643343 100644
--- a/wear/protolayout/protolayout-material/src/androidTest/java/androidx/wear/protolayout/material/layouts/TestCasesGenerator.java
+++ b/wear/protolayout/protolayout-material/src/androidTest/java/androidx/wear/protolayout/material/layouts/TestCasesGenerator.java
@@ -619,8 +619,8 @@
     @NonNull
     private static Box buildColoredBoxMSL(int color) {
         return new Box.Builder()
-                .setWidth(dp(60))
-                .setHeight(dp(60))
+                .setWidth(dp(45))
+                .setHeight(dp(45))
                 .setModifiers(
                         new Modifiers.Builder()
                                 .setBackground(