Add new ops ARGMAX and ARGMIN

Bug: 113558658
Test: NeuralNetworksTest_static
Change-Id: I8862d4062181689ce69ab65aa07c1b6af07ba567
Merged-In: I8862d4062181689ce69ab65aa07c1b6af07ba567
(cherry picked from commit cc31bd6622f5e01ab640916fbb26433dd4ff9db2)
diff --git a/neuralnetworks/1.2/types.hal b/neuralnetworks/1.2/types.hal
index 61970f0..fc2b540 100644
--- a/neuralnetworks/1.2/types.hal
+++ b/neuralnetworks/1.2/types.hal
@@ -26,7 +26,9 @@
  * The type of an operation in a model.
  */
 enum OperationType : @1.1::OperationType {
-
+    // TODO: Sync docs.
+    ARGMAX = 38,
+    ARGMIN = 39,
 };
 
 /**