Build rules for compat config docs.

Add compat_config to offline SDK docs for now, to generate the
compatibility changes documentation.

Test: m -j offline-sdk-docs
Bug: 144927670
Change-Id: I856a0972212cb23ff97800243671e9c8280d5287
diff --git a/ApiDocs.bp b/ApiDocs.bp
index c40004c..04ddc50 100644
--- a/ApiDocs.bp
+++ b/ApiDocs.bp
@@ -176,6 +176,7 @@
     hdf: [
         "android.whichdoc offline",
     ],
+    compat_config: ":global-compat-config",
     proofread_file: "offline-sdk-docs-proofrerad.txt",
     args: framework_docs_only_args + " -offlinemode -title \"Android SDK\"",
     static_doc_index_redirect: "docs/docs-preview-index.html",