Add incremental_apk_by_default GN arg.

net/android/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 
 android_library("net_java") {
   java_files = [
     "java/src/org/chromium/net/AndroidCellularSignalStrength.java",
@@ skipping 76 matching lines @@
 shared_library("net_java_test_native_support") {
   testonly = true
   deps = [
     ":java_test_native_support",
     "//net:test_support",
   ]
 }
 
 android_apk("net_test_support_apk") {
   testonly = true
+
+  # Used as an additional_apk in test scripts.
+  never_incremental = true
   deps = [
     ":net_java_test_support",
     "//base:base_java",
   ]
   android_manifest = "../test/android/javatests/AndroidManifest.xml"
   apk_name = "ChromiumNetTestSupport"
   shared_libraries = [ ":net_java_test_native_support" ]
 }
 
 android_resources("net_unittests_apk_resources") {
@@ skipping 49 matching lines @@
   java_files =
       [ "junit/src/org/chromium/net/HttpNegotiateAuthenticatorTest.java" ]
   deps = [
     ":net_java",
     "//base:base_java",
     "//base:base_java_test_support",
     "//third_party/hamcrest:hamcrest_java",
   ]
   srcjar_deps = [ "//base:base_build_config_gen" ]
 }