buck2 for voltron language packs - 2

Summary:
Same like D51217538

Fix S378631,
It use buck2 build m4a build like [automation_messenger_for_perftest_playstoretest](D27298583) from v434, and the voltron language pack only contains 75k, see here https://www.internalfb.com/intern/mobile/buildinfo/buildinfo/?build=534694874 , I found out it is caused by buck2 it didn't build correct number of voltron string resources.

The repro way is to build following command
```
buck2 build --show-output fbsource//fbandroid/apps/messenger:messenger_staticdi_dlstr_arm64_filtered_str_debug#generate_voltron_string_resources
```
And the output only contains 10+ folders, if we check the path folder in `resource_dirs_for_voltron_string_source_map`, we will find out the it used filtered_res, which is for non-voltron language packs.

I checked the code and find out the fix can be just provide the correct folder, since the voltron folder was already there, but never correctly being used.

Reviewed By: luluonet

Differential Revision: D51228314

fbshipit-source-id: 3e65f1bca43bb21374c9dea954027ac5207d315c

prelude/android/android_binary_resources_rules.bzl

@@ -319,6 +319,7 @@ def _maybe_filter_resources(
             manifest_file = resource.manifest_file,
             r_dot_java_package = resource.r_dot_java_package,
             res = filtered_res,
+            voltron_res = voltron_res_info_to_out_res_dir[resource] if is_voltron_language_pack_enabled else None,
             text_symbols = resource.text_symbols,
         )
         filtered_resource_infos.append(filtered_resource)
@@ -356,7 +357,11 @@ def _maybe_generate_string_source_map(
         return None
 
     prefix = "voltron_" if is_voltron_string_source_map else ""
-    res_dirs = [resource_info.res for resource_info in resource_infos]
+    res_dirs = []
+    if is_voltron_string_source_map:
+        res_dirs = [resource_info.voltron_res for resource_info in resource_infos if resource_info.voltron_res != None]
+    if len(res_dirs) == 0:
+        res_dirs = [resource_info.res for resource_info in resource_infos]
     output = actions.declare_output("{}string_source_map".format(prefix), dir = True)
     res_dirs_file = actions.write("resource_dirs_for_{}string_source_map".format(prefix), res_dirs)
     generate_string_source_map_cmd = cmd_args([

prelude/android/android_providers.bzl

@@ -195,6 +195,8 @@ AndroidResourceInfo = provider(
         "r_dot_java_package": provider_field(typing.Any, default = None),  # Artifact | None
         # resources defined by this rule. May be empty
         "res": provider_field(typing.Any, default = None),  # Artifact | None
+        # voltron resources defined by this rule. May be empty
+        "voltron_res": provider_field(typing.Any, default = None),  # Artifact | None
         # priority of the resources, may be 'low' or 'normal'
         "res_priority": provider_field(typing.Any, default = None),  # str
         # symbols defined by the resources, if resources are present