Ensure reported unconverted deps are unique

Test: m bp2build
Change-Id: I4a260d1f2ff9f6fd39c55c447466618fcdef52c7
diff --git a/android/module.go b/android/module.go
index 6c7fc65..189781a 100644
--- a/android/module.go
+++ b/android/module.go
@@ -1290,7 +1290,7 @@
 // GetUnconvertedBp2buildDeps returns the list of module names of this module's direct dependencies that
 // were not converted to Bazel.
 func (m *ModuleBase) GetUnconvertedBp2buildDeps() []string {
-	return m.commonProperties.UnconvertedBp2buildDeps
+	return FirstUniqueStrings(m.commonProperties.UnconvertedBp2buildDeps)
 }
 
 func (m *ModuleBase) AddJSONData(d *map[string]interface{}) {