Add musl defaults in bp2build

Bug: 261657184
Test: Unit Tests
Test: Manual Inspection of generated files
Change-Id: I69864abb410fddecd530fc75f2531aff33b33c97
diff --git a/bazel/properties.go b/bazel/properties.go
index 76450dc..9037cac 100644
--- a/bazel/properties.go
+++ b/bazel/properties.go
@@ -814,6 +814,16 @@
 	return false
 }
 
+// HasAxisSpecificValues returns true if the attribute contains axis specific label list values from a given axis
+func (lla LabelListAttribute) HasAxisSpecificValues(axis ConfigurationAxis) bool {
+	for _, values := range lla.ConfigurableValues[axis] {
+		if !values.IsNil() {
+			return true
+		}
+	}
+	return false
+}
+
 // IsEmpty returns true if the attribute has no values under any configuration.
 func (lla LabelListAttribute) IsEmpty() bool {
 	if len(lla.Value.Includes) > 0 {