Add manifest-driven required mod imports

mobile/android/love/src/jni/love/src/modules/system/System.cpp

@@ -192,8 +192,12 @@ bool System::pickFile(const char *kind) const
 			dest = "picked_mod.zip";
 		else if (strcmp(kind, "sav") == 0 || strcmp(kind, "save") == 0)
 			dest = "picked_save.sav";
+		else if (strcmp(kind, "required_import") == 0)
+			dest = "picked_required_import.bin";
 		else if (strcmp(kind, "rom") == 0)
 			dest = "picked_rom.gb";
+		else
+			return false;
 	}
 	return love::android::showFilePicker(dest);
 #else
@@ -202,6 +206,15 @@ bool System::pickFile(const char *kind) const
 #endif
 }
 
+const char *System::pickFileKinds() const
+{
+#ifdef LOVE_ANDROID
+	return "rom,mod,sav,required_import";
+#else
+	return "";
+#endif
+}
+
 bool System::createFile(const char *suggestedName) const
 {
 #ifdef LOVE_ANDROID

mobile/android/love/src/jni/love/src/modules/system/System.h

@@ -112,10 +112,12 @@ public:
 	 * love::android::showFilePicker and src/import/RomImporter.lua.
 	 *
 	 * @param kind Optional pick kind: nullptr/"rom" -> picked_rom.gb,
-	 *             "mod" -> picked_mod.zip, "sav"/"save" -> picked_save.sav.
+	 *             "mod" -> picked_mod.zip, "sav"/"save" -> picked_save.sav,
+	 *             "required_import" -> picked_required_import.bin.
 	 * @return Whether the picker was shown.
 	 **/
 	virtual bool pickFile(const char *kind = nullptr) const;
+	virtual const char *pickFileKinds() const;
 
 	/**
 	 * Shows the platform's native "create / save a file" UI (Android SAF

mobile/android/love/src/jni/love/src/modules/system/wrap_System.cpp

@@ -102,6 +102,12 @@ int w_pickFile(lua_State *L)
 	return 1;
 }
 
+int w_pickFileKinds(lua_State *L)
+{
+	luax_pushstring(L, instance()->pickFileKinds());
+	return 1;
+}
+
 int w_createFile(lua_State *L)
 {
 	const char *suggested = luaL_optstring(L, 1, nullptr);
@@ -222,6 +228,7 @@ static const luaL_Reg functions[] =
 	{ "openURL", w_openURL },
 	{ "vibrate", w_vibrate },
 	{ "pickFile", w_pickFile },
+	{ "pickFileKinds", w_pickFileKinds },
 	{ "createFile", w_createFile },
 	{ "syncHealthSteps", w_syncHealthSteps },
 	{ "restartApp", w_restartApp },