[MNG-8178] Fall back to system properties for missing profile activation context properties (#1609)

Missed port to the build implementation from f2a0865

Author: gnodet

maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/profile/OperatingSystemProfileActivator.java

@@ -56,9 +56,15 @@ public boolean isActive(Profile profile, ProfileActivationContext context, Model
 
         boolean active = ensureAtLeastOneNonNull(os);
 
-        String actualOsName = context.getSystemProperties().get("os.name").toLowerCase(Locale.ENGLISH);
-        String actualOsArch = context.getSystemProperties().get("os.arch").toLowerCase(Locale.ENGLISH);
-        String actualOsVersion = context.getSystemProperties().get("os.version").toLowerCase(Locale.ENGLISH);
+        String actualOsName = context.getSystemProperties()
+                .getOrDefault("os.name", Os.OS_NAME)
+                .toLowerCase(Locale.ENGLISH);
+        String actualOsArch = context.getSystemProperties()
+                .getOrDefault("os.arch", Os.OS_ARCH)
+                .toLowerCase(Locale.ENGLISH);
+        String actualOsVersion = context.getSystemProperties()
+                .getOrDefault("os.version", Os.OS_VERSION)
+                .toLowerCase(Locale.ENGLISH);
 
         if (active && os.getFamily() != null) {
             active = determineFamilyMatch(os.getFamily(), actualOsName);