Optimize HasIntersection

Just noticed it was wildly unoptimized while making
a different change.

Test: m nothing --no-skip-soong-tests
Change-Id: I319a1f5ebc1269c5949735e77ec3bd8ef6ee95ee

1 files changed, 7 insertions, 2 deletions

diff --git a/android/util.go b/android/util.go
index 30d8ec6b3..b9ab77aec 100644
--- a/android/util.go
+++ b/android/util.go
@@ -238,8 +238,13 @@ func ListSetDifference[T comparable](l1, l2 []T) (bool, []T, []T) {
 
 // Returns true if the two lists have common elements.
 func HasIntersection[T comparable](l1, l2 []T) bool {
-	_, a, b := ListSetDifference(l1, l2)
-	return len(a)+len(b) < len(setFromList(l1))+len(setFromList(l2))
+	m1 := setFromList(l1)
+	for _, x := range l2 {
+		if _, ok := m1[x]; ok {
+			return true
+		}
+	}
+	return false
 }
 
 // Returns true if the given string s is prefixed with any string in the given prefix list.