Change ColorStop.getColor return type to NonNull.

The color field is mandatory and always set.

Change-Id: I7a6894324c9ffbaaf692678baaa41af45b847864
BUG: 301582140

diff --git a/wear/protolayout/protolayout/api/current.txt b/wear/protolayout/protolayout/api/current.txt
index aaaddce..69123be5 100644
--- a/wear/protolayout/protolayout/api/current.txt
+++ b/wear/protolayout/protolayout/api/current.txt

@@ -124,7 +124,7 @@
   public static final class ColorBuilders.ColorStop {
     ctor public ColorBuilders.ColorStop(androidx.wear.protolayout.ColorBuilders.ColorProp);
     ctor public ColorBuilders.ColorStop(androidx.wear.protolayout.ColorBuilders.ColorProp, androidx.wear.protolayout.TypeBuilders.FloatProp);
-    method public androidx.wear.protolayout.ColorBuilders.ColorProp? getColor();
+    method public androidx.wear.protolayout.ColorBuilders.ColorProp getColor();
     method public androidx.wear.protolayout.TypeBuilders.FloatProp? getOffset();
   }
 

diff --git a/wear/protolayout/protolayout/api/restricted_current.txt b/wear/protolayout/protolayout/api/restricted_current.txt
index aaaddce..69123be5 100644
--- a/wear/protolayout/protolayout/api/restricted_current.txt
+++ b/wear/protolayout/protolayout/api/restricted_current.txt

@@ -124,7 +124,7 @@
   public static final class ColorBuilders.ColorStop {
     ctor public ColorBuilders.ColorStop(androidx.wear.protolayout.ColorBuilders.ColorProp);
     ctor public ColorBuilders.ColorStop(androidx.wear.protolayout.ColorBuilders.ColorProp, androidx.wear.protolayout.TypeBuilders.FloatProp);
-    method public androidx.wear.protolayout.ColorBuilders.ColorProp? getColor();
+    method public androidx.wear.protolayout.ColorBuilders.ColorProp getColor();
     method public androidx.wear.protolayout.TypeBuilders.FloatProp? getOffset();
   }
 

diff --git a/wear/protolayout/protolayout/src/main/java/androidx/wear/protolayout/ColorBuilders.java b/wear/protolayout/protolayout/src/main/java/androidx/wear/protolayout/ColorBuilders.java
index 544b9c8..9060fc0 100644
--- a/wear/protolayout/protolayout/src/main/java/androidx/wear/protolayout/ColorBuilders.java
+++ b/wear/protolayout/protolayout/src/main/java/androidx/wear/protolayout/ColorBuilders.java

@@ -214,13 +214,9 @@
          *
          * @since 1.3
          */
-        @Nullable
+        @NonNull
         public ColorProp getColor() {
-            if (mImpl.hasColor()) {
-                return ColorProp.fromProto(mImpl.getColor());
-            } else {
-                return null;
-            }
+            return ColorProp.fromProto(mImpl.getColor());
         }
 
         /**