[Android] Enable multidex for release builds of chrome_public_test_apk.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index e6b2c640dc87b3e3baee5a0b7795ebf4ecd0b276..b623e963250371f25eaf56e7dceef972fc850745 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -2593,7 +2593,9 @@ 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/PackageManagerWrapper.java",
       "test/android/javatests/src/org/chromium/base/test/SetUpTestRule.java",
       "test/android/javatests/src/org/chromium/base/test/SetUpStatement.java",
       "test/android/javatests/src/org/chromium/base/test/util/AdvancedMockContext.java",