[Android] Enable multidex for release builds of chrome_public_test_apk. (RELAND)

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index 7a971d9e386df0312831ad325da7774eb8904d16..aea9c56c904f8e72db264cceecc41d91ce217ea4 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -2583,6 +2583,7 @@ if (is_android) {
       "//testing/android/reporter:reporter_java",
       "//third_party/android_support_test_runner:exposed_instrumentation_api_publish_java",
       "//third_party/android_support_test_runner:runner_java",
+      "//third_party/android_tools:android_support_chromium_java",
       "//third_party/hamcrest:hamcrest_core_java",
       "//third_party/junit",
     ]
@@ -2592,6 +2593,7 @@ if (is_android) {
       "test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java",
       "test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java",
       "test/android/javatests/src/org/chromium/base/test/BaseChromiumAndroidJUnitRunner.java",
+      "test/android/javatests/src/org/chromium/base/test/BaseChromiumRunnerCommon.java",
       "test/android/javatests/src/org/chromium/base/test/BaseTestResult.java",
       "test/android/javatests/src/org/chromium/base/test/util/AdvancedMockContext.java",
       "test/android/javatests/src/org/chromium/base/test/util/CallbackHelper.java",