Register FlagManager as a System Service

Flag: android.provider.flags.stage_flags_for_build
Test: m
Bug: 372729920
Change-Id: I3e24c81033a0026035d64a9b148f655e1a040d09
diff --git a/Android.bp b/Android.bp
index 48f0928..c57ff56 100644
--- a/Android.bp
+++ b/Android.bp
@@ -398,6 +398,7 @@
         "bouncycastle-repackaged-unbundled",
         "com.android.sysprop.foldlockbehavior",
         "com.android.sysprop.view",
+        "configinfra_framework_flags_java_lib",
         "framework-internal-utils",
         "dynamic_instrumentation_manager_aidl-java",
         // If MimeMap ever becomes its own APEX, then this dependency would need to be removed