libhidl_gtest_helpers -> libhidl_gtest_helper

Singular name is more common.

Bug: N/A
Test: N/A
Change-Id: I65eb36e951134ee63c7d85365083de0a7673ba34
diff --git a/Android.bp b/Android.bp
index 70e0574..f64968f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -26,7 +26,7 @@
     ],
 
     header_libs: [
-        "libhidl_gtest_helpers",
+        "libhidl_gtest_helper",
     ],
 
     group_static_libs: true,