Ignore owner property when computing java_sdk_library dist subdirectory

The owner property is no longer used, the dist subdirectory is determined
by the dist_group property.

Bug: 186723288
Test: TestJavaSdkLibraryDist
Change-Id: Id6d997eef05f6511070677974219674f248cb754
diff --git a/java/sdk_library.go b/java/sdk_library.go
index 1936bf5..7fec138 100644
--- a/java/sdk_library.go
+++ b/java/sdk_library.go
@@ -1233,14 +1233,7 @@
 
 // distGroup returns the subdirectory of the dist path of the stub artifacts.
 func (module *SdkLibrary) distGroup() string {
-	if group := proptools.String(module.sdkLibraryProperties.Dist_group); group != "" {
-		return group
-	}
-	// TODO(b/186723288): Remove this once everything uses dist_group.
-	if owner := module.ModuleBase.Owner(); owner != "" {
-		return owner
-	}
-	return "unknown"
+	return proptools.StringDefault(module.sdkLibraryProperties.Dist_group, "unknown")
 }
 
 func (module *SdkLibrary) latestApiFilegroupName(apiScope *apiScope) string {