Fix unautoloadable FacebookAds classes in capi-param-builder (PSR-4 violation breaking php-business-sdk)

Summary:
GitHub issue #36: `FacebookAds\PII_DATA_TYPE` is not autoloadable in 1.3.1, which breaks `facebook/php-business-sdk` 25.0.2 — `UserData::normalize()` calls `FacebookAds\PII_DATA_TYPE::EMAIL`, and any server-side Conversions API event fatals with `Class "FacebookAds\PII_DATA_TYPE" not found`.

Root cause: the package's only autoload rule is `psr-4: { "FacebookAds\\": "src/" }`, but `PII_DATA_TYPE` (and in fact all 15 classes under `src/model/`, `src/util/`, `src/piiUtil/`) declare the flat `namespace FacebookAds;` while living in subdirectories. Under PSR-4, `FacebookAds\PII_DATA_TYPE` must resolve to `src/PII_DATA_TYPE.php`; Composer never looks in `src/model/Constants.php`, so `class_exists('FacebookAds\PII_DATA_TYPE')` returns false. The package itself only works today via manual `require_once` chains, but a downstream consumer that references the class through Composer autoloading (like the SDK) fatals.

Fix: add a `classmap` autoload entry for the three subdirectories alongside the existing PSR-4 map. Composer's classmap maps a class to its file by scanning declarations regardless of filename or directory, so `FacebookAds\PII_DATA_TYPE` and the other 14 subdirectory classes become autoloadable while every fully-qualified class name stays exactly as-is (important: the SDK depends on the flat `FacebookAds\PII_DATA_TYPE` FQN, so renaming/re-namespacing is not an option). This is the maintainer-suggested fix from the issue and requires no file moves or namespace changes. Also bumped the package version 1.3.1 -> 1.3.2 so the fix ships as a new release.

___

Differential Revision: D112249764

fbshipit-source-id: 7f5b758a5f93683daa182bc1fd7aecfec869233e

Author: Yin Liu

php/capi-param-builder/composer.json

@@ -1,6 +1,6 @@
 {
   "name": "facebook/capi-param-builder-php",
-  "version": "1.3.1",
+  "version": "1.3.2",
   "description": "Parameter builder SDK for Conversion API events",
   "require": {
     "php": ">=7.4"
@@ -12,7 +12,12 @@
   "autoload": {
     "psr-4": {
       "FacebookAds\\": "src/"
-    }
+    },
+    "classmap": [
+      "src/model/",
+      "src/util/",
+      "src/piiUtil/"
+    ]
   },
   "autoload-dev": {
     "psr-4": {