Add incremental_apk_by_default GN arg.

build/config/android/internal_rules.gni

Index: build/config/android/internal_rules.gni
diff --git a/build/config/android/internal_rules.gni b/build/config/android/internal_rules.gni
index 48fcbc4e71891f8a8c32cedea9a369fe1570c889..80a6af0cb492dfb6f0d36f39d02de2cf86b65fe9 100644
--- a/build/config/android/internal_rules.gni
+++ b/build/config/android/internal_rules.gni
@@ -557,9 +557,17 @@ template("test_runner_script") {
         _build_config = get_label_info(additional_apk, "target_gen_dir") + "/" +
                         get_label_info(additional_apk, "name") + ".build_config"
         _rebased_build_config = rebase_path(_build_config, root_build_dir)
+
+        _additional_apk_path =
+            "@FileArg($_rebased_build_config:deps_info:apk_path)"
+        if (_incremental_install) {
+          _additional_apk_path =
+              "@FileArg($_rebased_build_config:deps_info:incremental_apk_path)"
+        }
+
         test_runner_args += [
           "--additional-apk",
-          "@FileArg($_rebased_build_config:deps_info:apk_path)",
+          _additional_apk_path,
         ]
       }
     }