Add OWNERS for SdkExtension cts test

They're used for filing bugs about failing tests.

Bug: 137191822
Test: N/A
Change-Id: I9e827e9fe1096d394481dbea10fa2888e6f50e3d
diff --git a/tests/tests/sdkext/OWNERS b/tests/tests/sdkext/OWNERS
new file mode 100644
index 0000000..feb2742
--- /dev/null
+++ b/tests/tests/sdkext/OWNERS
@@ -0,0 +1 @@
+hansson@google.com