Move ChromiumMultiDex to BuildConfig.

build/config/android/rules.gni

Index: build/config/android/rules.gni
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 2c52058787929b510c0089c74f29c60c11be3750..3fccee6b2e4b8e84a480c622db49e11d2063fce8 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1528,10 +1528,10 @@ template("android_apk") {
   }
 
   if (!defined(invoker.apk_under_test)) {
-    java_cpp_template("${_template_name}__multidex_config_java") {
-      package_name = "org/chromium/base/multidex"
+    java_cpp_template("${_template_name}__build_config_java") {
+      package_name = "org/chromium/base"
       sources = [
-        "//base/android/java/templates/ChromiumMultiDex.template",
+        "//base/android/java/templates/BuildConfig.template",
       ]
 
       defines = []
@@ -1539,7 +1539,7 @@ template("android_apk") {
         defines += [ "ENABLE_MULTIDEX" ]
       }
     }
-    _srcjar_deps += [ ":${_template_name}__multidex_config_java" ]
+    _srcjar_deps += [ ":${_template_name}__build_config_java" ]
   }
 
   java_target = "${_template_name}__java"