[GN] Add support for generated proguard configs in android_apk

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 2cc550bc3dade4091a87d0af802e73299303dd0f..3e9c66bc4d91e1afc5bfde64397a99024b7cd74c 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1834,9 +1834,13 @@ if (enable_java_templates) {
         forward_variables_from(invoker,
                                [
                                  "alternative_android_sdk_jar",
+                                 "deps",
                                  "proguard_jar_path",
                                ])
-        deps = [
+        if (!defined(deps)) {
+          deps = []
+        }
+        deps += [
           ":$build_config_target",
           ":$java_target",
           ":$process_resources_target",