Add healthfitness sources to framework-doc-system-stubs.

This will allow us to use the HealthFitness APIs across the framework,
most immediately for permissions.

Bug: 378992337
Change-Id: Iccd7c8efdff68e7d26d8f16d02ab361788cd6fda
Flag: EXEMPT DOCS_ONLY
Test: m framework-doc-system-stubs
diff --git a/api/ApiDocs.bp b/api/ApiDocs.bp
index 1ebe0cd..89351fd 100644
--- a/api/ApiDocs.bp
+++ b/api/ApiDocs.bp
@@ -61,6 +61,7 @@
         ":framework-bluetooth-sources",
         ":framework-connectivity-tiramisu-updatable-sources",
         ":framework-graphics-srcs",
+        ":framework-healthfitness-sources",
         ":framework-mediaprovider-sources",
         ":framework-nearby-sources",
         ":framework-nfc-updatable-sources",